Treating the chronic abdominal pain felt by people who have irritable bowel syndrome can be frustrating to both patients and physicians. If the diagnosis of IBS has not yet been made, it is frustrating that diagnostic studies and tests repeatedly turn up normal or “negative” instead of providing a clear reason for the symptoms. Chronic abdominal pain can be quite difficult to treat, and in people who have IBS, the abdominal pain tends to be persistent or recurring. In addition, it is bothersome that even if the altered bowel habits of IBS are eased, the abdominal pain can persist. These problems are well illustrated by the case of Maria, a patient who has IBS and chronic abdominal pain.
When Maria was 32, she visited a new internist for a third opinion about her long history of abdominal pain and altered bowel habits. Her pain had begun during her senior year of high school after she was robbed. Although she was not injured physically, she was severely traumatized emotionally. She cancelled her plans to go to college and instead took on a part-time job. She moved in with her boyfriend, but that relationship soured and she lived on her own for the next several years. She worked at a variety of jobs during that time, but they usually ended up with her quitting or being fired. Maria dated several men during the next few years, but each relationship was fairly short lived.
In her mid-twenties Maria developed problems with lower abdominal pain and intermittent diarrhea. At first the diarrhea and pain occurred once or twice a week, usually as she was getting ready to go to work. She saw her primary care physician, who told her that the abdominal pain was probably just a spasm of her GI tract and that avoiding milk products and minimizing fiber would relieve her symptoms. These changes did not help her pain and, in fact, her symptoms worsened. At the time of her follow-up visit her doctor ordered some laboratory tests and an ultrasound of her abdomen. Both tests yielded normal results. Maria was relieved to hear that the tests were normal, but she wondered why she was still having the pain, which was occurring even more frequently. Maria’s doctor prescribed hyoscyamine, a medication designed to relax the smooth muscle of the GI tract. It seemed to work only intermittently.
Maria’s symptoms intensified over the next several years, becoming significantly worse after her mother died of ovarian cancer. She became depressed and withdrew from family and friends. Maria did some reading at the library and some research on the Internet and became convinced that her symptoms meant that she, too, had ovarian cancer. Her doctor listened carefully, performed a thorough physical examination, and made an appointment for her to see a gynecologist for a complete pelvic examination. This exam was normal, but the gynecologist ordered some specialized blood tests and a CT scan of the abdomen and pelvis to eliminate any possibility of cancer and, she hoped, to reassure Maria. Fortunately, these tests all came back normal.
Maria noted a further worsening of her pain, however, and she was next referred to a gastroenterologist. A colonoscopy was scheduled, because of her chronic diarrhea. The colonoscopy, including biopsies (samples of tissue) of the colon, revealed no abnormalities. Again Maria was pleased by the test results but wondered why she still had pain every day. The gastroenterologist gave her a prescription for dicyclo-mine (another medication to relax the smooth muscle of the GI tract) and told her to use the medication regularly for her abdominal pain. He also prescribed Lomotil, for her diarrhea. On this regimen, Maria’s diarrhea improved, but her abdominal pain worsened. She stopped going to work because she said it hurt too much to work. She lost her job and filed for medical disability. During the next 6 months, Maria gained over 45 pounds, which made her even more depressed. She saw a second gastroenterologist, who performed an upper endoscopy (also called an EGD); this test was also normal. Blood work was ordered to measure the function of her thyroid, liver, and pancreas, and all results were normal.
Maria went to see another internist. This doctor recognized Maria’s depression and gave her a prescription for an antidepressant; however, Maria did not fill the prescription. Shortly thereafter, because of severe abdominal pain, Maria went to the emergency room late one winter evening. The emergency room was extremely busy, because several automobile accidents had occurred at once. A young doctor there reviewed her records, performed a brief examination, and gave her six tablets of Percocet (a type of narcotic). As she took one Percocet tablet twice a day for the next three days, Maria finally obtained some relief from her chronic abdominal pain. However, after the medication ran out, her pain reappeared. She went back to see her most recent internist and requested a renewal of the Percocet. The doctor refused, stating that she did not prescribe narcotics for the treatment of chronic abdominal pain.
Out of frustration, and because of continued pain, Maria made an appointment with a surgeon, who ordered an ultrasound of her gallbladder and a test to measure how well the gallbladder emptied bile into the small intestine. Although the ultrasound looked normal, he said that the pain might be due to the gallbladder emptying bile a little more slowly than normal. He recommended that she have her gallbladder out. She agreed, convinced that this would cure her pain. After her gallbladder was removed, Maria noted an improvement in her pain for about a week, while she was on postsurgical pain medication, but then all of her symptoms returned and her diarrhea worsened. She then consulted a third gastroenterologist, who repeated some of the blood tests and ordered another CT scan of her abdomen and pelvis. These tests were once again normal. This doctor prescribed Donnatal (another medication to help the smooth muscle of the GI tract relax) twice a day with Lomotil four times a day. This combination of medications helped her diarrhea, but her daily abdominal pain continued. She then made an appointment to see a third internist, to discuss her abdominal pain.
Although Maria’s case may seem complex and drawn out, her story is not all that uncommon. Chronic abdominal pain can persist for years and often leads to extensive and sometimes unnecessary testing, repeated and expensive doctor visits, and even unnecessary surgery. In fact, several good research studies have shown that women who have IBS are two to three times more likely than women who do not have IBS to have unnecessary surgery, including unnecessary removal of the gallbladder, appendix, and uterus.
The section below reviews current concepts about why abdominal pain occurs in people who have IBS and discusses the treatment options that are available. The chapter concludes with a look at the possibility of treating the totality of symptoms of IBS, by definition a multisymptom condition. Identifying one medication that is best for all patients who have IBS is not possible. Within a given class of drug, most of these medications are not significantly better or worse than the others. Finding the right one or ones for an individual person is often a matter of trial and error, to determine which medication provides the best relief of symptoms with the fewest side effects in that patient.
Persistent, intractable, or recurrent abdominal pain is the most common reason why people who have IBS make an appointment to see a physician. Many people who have IBS learn to cope with their constipation or diarrhea, no matter how inconvenient or disabling these symptoms may be. They use over-the-counter medications to minimize symptoms, they adapt to their symptoms by adjusting work or travel schedules, and they just generally learn to live with their bowel patterns. But abdominal pain is a different matter. Over-the-counter remedies (aspirin, acetaminophen, and anti-inflammatory agents like Motrin or Advil) are rarely effective in the treatment of IBS.
Chronic abdominal pain can significantly impede daily function and is obviously unpleasant. No one likes to suffer from pain, whether it’s from a migraine headache, a twisted ankle, or chronic abdominal pain from IBS. It can disrupt school and work and can significantly diminish the quality of daily life on multiple levels—physical, emotional, and mental. In addition, chronic pain can be exhausting, both mentally and physically; persistent pain, of any sort, wears people down. It may lead to anger, pessimism, hopelessness, and even depression. Finally, the fact that relief cannot be obtained with simple over-the-counter remedies often causes people to worry that something serious “must be going on” inside of their body, and they fear that the pain is due to cancer.
For some people who have IBS, the abdominal pain is just an intermittent annoyance, while for others it may be excruciating and disabling. Some patients describe the pain as a dull ache or discomfort; others call it crampy or like a spasm. Still others describe their pain as twisting, burning, or stabbing in nature. Most patients who have IBS have pain in the lower left quadrant or in the lower central pelvis, above the pubic bone. These are the areas, respectively, of the descending colon, sigmoid colon, and rectum. However, IBS pain may occur anywhere throughout the abdomen. Most individuals who have IBS have a pattern of pain that is typical for them and does not change over time. The pain may change in intensity, but the character of the pain tends to remain the same.
Abdominal pain is experienced by people who have IBS for four main reasons. One, extraordinarily strong contractions can occur in the smooth muscle that lines the colon and small intestine. Two, it appears that people who have IBS are more sensitive to stimulation in the GI tract (heightened visceral sensitivity). Three, patients who have IBS appear to perceive pain differently in their brain. The ability to “block out” or ignore painful sensations from the gut is lower in patients who have IBS than in people who do not have IBS; thus, a greater proportion of painful sensations from the gut are sensed. Four, distention of the colon or small intestine from gas may cause pain or discomfort for some patients (this is discussed in Chapter 3).
Medications currently available to treat chronic abdominal pain are listed in Table 18.1 and discussed below.
Medications that relieve pain are classified as analgesics (an means “without”; algesia means “pain”). Many over-the-counter analgesic agents are now available. They fall into one of three main categories. One category is products that contain aspirin (Bufferin, Excedrin, etc.). Aspirin, derived from the bark of the willow tree, has been used to treat pain since at least the 1700s. Aspirin was formally introduced in 1899, and it is estimated that as much as twenty thousand tons of it is used each year in the United States alone. Aspirin acts to reduce fever and inflammation in the body. A second category of analgesic contains acetaminophen (for example, Tylenol). Acetaminophen was introduced in 1893, although it has only become really popular in the last 50 years. It is used to treat mild to moderate pain of various causes. Like aspirin, it reduces fever, but it has minimal anti-inflammatory effect. The third category is nonsteroidal anti-inflammatory drugs (NSAIDs, such as Motrin, Advil, Ibuprofen, and Aleve). These medications are used for mild to moderate pain; they reduce fever and treat inflammation.
Table 18.1. Medications Used to Treat Abdominal Pain
Smooth-muscle antispasmodics Hyoscyamine (Levsin) Dicyclomine (Bentyl) Librax (chlordiazepoxide + clidinium) Donnatal (phenobarbital + atropine + hyoscyamine + scopolamine) Glycopyrrolate (Robinul) Anticholinergic agents Atropine Glycopyrrolate (Robinul) Hyoscyamine (Levsin) Scopolamine Methscopolamine (Pamine) Tricyclic antidepressants Amitriptyline (Elavil) Desipramine (Norpramin) Doxepin (Sinequan) Imipramine (Tofranil) Nortriptyline (Pamelor) Selective serotonin reuptake inhibitors (SSRIs) Herbal remedies and alternative therapies Peppermint oil Ginger Aloe Acupuncture Miscellaneous Carbamazepine (Tegretol) Phenytoin (Dilantin) Tramadol (Ultram) Gabapentin (Neurontin) Pregabalin (Lyrica) |
All three types of analgesic are generally effective at treating the everyday aches and pains that we all occasionally suffer, including mild headaches, muscle aches and pains from a cold or flu, muscle pain from doing too much heavy lifting, or joint pain from arthritis. These products are also considered relatively safe if taken at the recommended doses for short periods of time. However, chronic use of either aspirin products or NSAIDs increases the risk of internal bleeding, most commonly from an ulcer in the stomach or small intestine. Chronic use or short-term high-dose use of acetaminophen (especially when combined with alcohol) can injure the liver. Unfortunately, none of these agents seems to provide any significant relief from the recurrent abdominal pain that typifies IBS. Physiologically, this makes sense, because both aspirin and NSAIDs are designed to treat inflammation, and irritable bowel syndrome is not an inflammatory condition.
Over the last two decades, the group of prescription medications labeled smooth-muscle antispasmodic agents has evolved into a mainstay of therapy for treating patients who have IBS and abdominal pain. These agents act throughout the GI tract to relax smooth muscle. By relaxing the smooth muscle of the gut, these agents can help relieve the spasms (hence the name antispasmodic) and cramps that are often associated with abdominal pain. Some patients who have IBS and diarrhea find that these medications also help with the sensation of urgency that can accompany diarrhea. Other patients report that antispasmodic agents help with bloating and distention. These medications function primarily by blocking the neurotransmitter vital to muscle contraction, acetylcholine, so, in fact, they are anticholinergic agents (see below).
Ample theoretical grounds exist for prescribing antispasmodic medications, but research studies of them during the last two decades have been few and small scale, although positive. Several small studies in Europe showed that they improved abdominal pain. In addition, a meta-analysis of the data from all of the published research studies found that smooth-muscle antispasmodics improved symptoms of abdominal pain for patients who had IBS. Unfortunately, none of the medications tested in the European studies is currently available in the United States. One study performed in the United States over 25 years ago did show that 40 mg of one of these drugs, dicyclomine hydrochloride (Bentyl), taken 4 times a day improved symptoms of abdominal pain in patients who had IBS. Approximately two-thirds of the patients enrolled in that study suffered side effects, but the dose they were taking is higher than that prescribed by most physicians. In summary, although they are widely used, we have little data on these agents from research studies performed in the United States.
Many patients who have IBS find that their symptoms improve with antispasmodic drugs, particularly if those symptoms are precipitated by meals and sensations of fecal urgency. Despite the limited evidence available to support their use, these medications are commonly prescribed by physicians. This practice may reflect the fact that these drugs provide greater benefits in the clinical setting than have been reported in the research studies or simply that few other options exist.
What recommendations can be given regarding the use of smooth-muscle antispasmodics? For the majority of patients, these medications are best used as needed (p.r.n.) rather than on a regular basis. Some people find that the beneficial effects of antispasmodics wear off over time if they are used on a daily basis. (This raises the issue of whether one develops a tolerance to these medications, a question that has not been studied.) When used for meal-induced symptoms, antispasmodics should be taken 30 to 60 minutes before meals so that peak blood levels of the drug coincide with peak symptoms. Because these medications improve symptoms of abdominal pain for some patients who have IBS, and because they have an extremely low potential for addiction, they can safely be used on an intermittent basis to treat abdominal pain in patients who have IBS. However, they will not cure IBS. Side effects of these agents include dry mouth, dry eyes, difficulty concentrating, urine hesitancy, and fatigue.
Hyoscyamine is one of the most commonly prescribed smooth-muscle antispasmodics. It is available in three formulations: a sublingual (under-the-tongue) tablet, a slow-release form, and a liquid. The sublingual tablet (Levsin SL; NuLev) dissolves within minutes and reaches its peak effect in approximately 45 to 60 minutes, although the drug remains in the bloodstream for hours. The liquid (elixir) acts more quickly than the slow-release or sublingual forms. In our experience, the sublingual tablet and liquid can effectively minimize the cramps and urgency that develop after eating a meal. Some patients keep supplies of sublingual tablets at home, in their car, and at work, in order to be prepared at all times. The slow-release, long-acting form (Levsin SR) is taken orally either once or twice a day, depending on symptoms. Dicyclomine (Bentyl) is another commonly prescribed smooth-muscle antispasmodic. It comes in both pill and liquid forms and can be taken from one to four times a day. Its effects are similar to hyoscyamine.
Because both hyoscyamine and dicyclomine work by blocking the neurotransmitter (acetylcholine) that causes smooth muscles to contract throughout the body, these medications have a number of possible side effects. Common side effects are dry mouth or dry eyes, feeling sleepy or fatigued, urinary hesitancy, and difficulty concentrating. At higher doses, some patients note that they feel somewhat groggy throughout the day, become constipated, or have difficulty urinating. As with any medication, side effects can develop in some patients but not others who take the same dose. This can occur because of differences in the individuals’ size, age, other medications that are taken, use of alcohol or narcotics, frequency of dosing, and length of time the medication has been used.
Hyoscyamine and dicyclomine are generally safe to take with other medications; however if used with other medicines that have similar side effects (like anticholinergics or TCAs—see below), side effects could be worse. It is important to note that these medications should not be used if you have glaucoma, because they can worsen that eye disorder.
These two smooth-muscle antispasmodics are different from the two described above because they are mixtures of drugs rather than single agents. Librax is a mixture of chlordiazepoxide and clidinium. Chlordiazepoxide is a benzodiazepine, which is a class of drug that helps people to relax and eases anxiety. (Valium is one of the best-known benzodiazepines, although there are many others.) Clidinium is similar to hyoscyamine and dicyclomine. Librax is used to treat symptoms of abdominal pain, cramps, and urgency. It can be especially helpful for people who are also nervous or anxious, because the benzodiazepine component (chlordiazepoxide) helps to relieve anxiety. Librax is prescribed much less frequently than are dicyclomine and hyoscyamine, because many physicians are concerned about patients becoming addicted to the chlordiazepoxide component of the medication. Benzodiazepines, if not monitored carefully and used appropriately, can be addictive.
Donnatal is made up of four agents and is available in pill and liquid forms. Its components are hyoscyamine (an antispasmodic agent), atro-pine (an anticholinergic agent—see below), scopolamine (an anticholinergic agent), and phenobarbital (classified as an anticonvulsant, usually used to treat seizures). The inclusion of an anticonvulsant seems odd; however, research studies have shown that some medications used to treat seizures also ease nerve pain to a small degree. In addition, phenobarbital can induce mild sedation, which can be helpful for patients whose severe symptoms keep them from sleeping. Donnatal is rarely the first agent prescribed for patients who have IBS; rather, it is generally reserved for patients who have tried other medications but have not had any improvement and for patients who have particularly severe symptoms. Combination agents are sometimes more effective in treating abdominal spasms, cramps, and pain than any single agent.
Some patients and care providers feel that Donnatal causes fewer side effects than some of the other anticholinergic agents. This may be because the amounts of each component medication are much smaller than if the agents were used individually. Like Librax, Donnatal is best used on an as-needed basis for brief periods of time. Typical side effects are similar to those of Librax, although people may feel somewhat more fatigued or groggy on Donnatal, due to the inclusion of phenobarbital. Note that these medications should be used cautiously by people who have IBS and constipation, as opposed to those who have IBS and diarrhea, because they may worsen constipation.
Although this medication is classified as an anticholinergic agent (described in the next section), it is often used to treat spasms in the GI tract.
This category encompasses a large group of prescription medications, some of the most common being atropine, glycopyrrolate, scopolamine, and dicyclomine (dicyclomine is described above). Anticholinergic agents (as described in Chapter 17) block the effects of acetylcholine, a neurotransmitter that plays a critical role in gut motility. It signals the smooth muscle to contract. As we’ve discussed, this contraction is sometimes too strong in patients who have IBS, and the exaggerated contractions can be quite painful. When the effects of acetylcholine are blocked by anticholinergic agents, the smooth muscle of the GI tract relaxes. This reduces spasms, slows gut motility, and relieves the sense of discomfort or urgency associated with having a bowel movement in people who have IBS.
As noted in the previous section, Robinul is another medication used to treat spasms and overly strong contractions in the GI tract. However, it is less commonly prescribed than the other antispasmodic agents, because most health care providers think of it as a medication to reduce the production of saliva and bronchial secretions (conveniently in some circumstances, one of the most common side effects of smooth muscle antispasmodics is a dry mouth). No studies have compared Robinul to any of the other antispasmodic medications, so it is not possible to make a valid recommendation about which medication is better. Robinul is generally prescribed in 1-mg doses, taken twice daily.
Unlike the opiates (such as those in Imodium and Lomotil), anticholinergic agents do not have any potential for addiction, even if used for long periods of time. However, like the smooth-muscle antispasmodics, anticholinergic agents act throughout the body, which increases the likelihood that side effects will develop, especially if the dose of the medication is increased or taken more frequently. Potential side effects of anticholinergic agents include dry mouth, dry eyes, change in vision, difficulty urinating, fatigue, sleepiness, and, rarely, constipation.
Many people who have IBS become skeptical or even offended when they hear the word antidepressant. This is not surprising, because a large number of people who have IBS have been told that they are “crazy” or that their intestinal problems are “all in your head.” The symptoms of IBS are real; they are not “all in your head.” The tricyclic antidepressants (TCAs), although used extensively in the past to treat depression, are actually not very effective for that condition, especially when compared to the newer antidepressant drugs. However, several research studies have demonstrated that these medications, when used in low doses, improve symptoms of nerve pain. Most importantly, research studies have shown that TCAs can be very effective at treating chronic abdominal pain in patients who have IBS. While we continue to refer to these drugs by their original purpose, when used to treat IBS they are not being prescribed because the patient is depressed.
The exact mechanism by which TCAs relieve abdominal pain in patients who have IBS is unknown. They may affect the nerves that lead from the gut to the spinal cord and then the brain, or they may act directly on the brain, influencing how people sense pain in the gut, possibly by altering the thresholds for sensing pain in the central nervous system.
In contrast to both the smooth-muscle antispasmodics and the anticholinergic agents, which are best used as needed rather than taken regularly, tricyclic antidepressants are utilized most effectively with a routine schedule. It is safe to combine TCAs with most of the medications described above, and many patients find significant relief of their symptoms by taking a small dose of a TCA each evening and then using an antispasmodic as needed for intermittent episodes of cramping, spasm, or pain.
Many of the side effects of TCAs are the same as for the antispasmodics and anticholinergic agents: dry mouth, dry eyes, fatigue, and difficulty concentrating. Some patients find that their blood pressure decreases a small amount, while other patients may gain weight on these medications. One of the side effects most likely to occur is mild sedation. For that reason, most clinicians who prescribe TCAs ask patients to take them at night, so that they do not feel tired during the day. Since a large number of people who have IBS have some degree of insomnia, taking a TCA at night can have the advantage of improving that symptom as well.
Generally, TCAs can be used by patients who have IBS with diarrhea, constipation, or alternating bowel habits. At the low doses in which they are usually taken, they don’t cause constipation. However, some patients require higher doses for their abdominal pain, and as the dose is increased, constipation is more likely to develop. People who have IBS and constipation may find that TCAs improve their abdominal pain but worsen their constipation.
TCAs do not work immediately. Both patients and physicians need to remember that it may take four to six weeks before any significant benefits are noted. In addition, the dose may need to be slowly increased, extending the trial period to 12 to 16 weeks. Also, TCAs do not work in everyone. Some patients respond very well to these agents, whereas other patients do not respond at all. Some people respond to one TCA but not to another. Therefore, a patient and physician may decide to try a different TCA if the first one prescribed does not lead to any improvement in abdominal pain. Common TCAs include amitriptyline, nortriptyline, and desipramine.
Since TCAs are generally used in low doses to treat abdominal pain, patients with coexisting depression usually do not notice any improvement in that condition. However, tricyclic antidepressants are safe to take with other antidepressants, for example, the class of drugs known as SSRIs.
A newer class of drugs for the treatment of depression, selective serotonin reuptake inhibitors (SSRIs) are among the most commonly prescribed drugs worldwide. These medications are also effective in treating some people who have mild anxiety, obsessive-compulsive disorder, somatization disorders, and social phobias. Because many people who have moderate to severe IBS also suffer from depression, anxiety, or a somatization disorder, it seems only natural to evaluate the use of these medications in treating IBS. However, only a few studies have been done, primarily looking at how these medications improve pain and quality of life for patients who have IBS. The data available are limited and to some degree conflicting. One study of 23 patients who had IBS but did not have depression showed that citalopram (Celexa) significantly improved symptoms of IBS compared to a placebo. However, another study of 54 patients who had IBS found that citalopram did not improve IBS symptoms during an eight-week study period. A third study of 72 patients who had IBS found that paroxetine (Paxil) improved quality of life for these patients, although it did not improve their abdominal pain during the 12-week study. A fourth study found that fluoxetine (Prozac) did not improve symptoms of abdominal pain in patients who had IBS. No studies have been conducted using some of the other popular SSRIs, such as sertraline (Zoloft), venlafaxine (Effexor), desvenlafaxine (Pristiq), or escitalopram (Lexapro).
Thus, limited and even conflicting data exist on whether patients will have an improvement in their IBS symptoms when treated with an SSRI. This points out why further research is needed in the field of IBS in general and, in particular, with regard to the treatment of abdominal pain. A large research study involving hundreds or even thousands of patients will be required to sort out this complicated issue. I suspect that, once sufficient data are collected and evaluated, we will find that SSRIs lead to an improvement in patients who have IBS and suffer from coexisting anxiety and depression. When these disorders are under better control, most patients find that they can cope with their abdominal pain much better. Direct effects on abdominal pain may be discovered as well, possibly through the actions of SSRIs in the brain.
If you and your health care provider decide that you should try an SSRI, it is important to be aware that you may not notice any improvements in your mood or pain for at least three to six weeks. Your dosage will probably need to be adjusted at routine follow-up visits. Because these medications take a while to work, a reasonable therapeutic trial of any single agent usually requires a minimum of 8 to 12 weeks; by then you will know whether the medication has truly helped. Some patients find that the first SSRI they try does not work but that the second or third agent does. You will need to work closely with your health care provider to find the most appropriate medication and the best dose for you. Although these medications are generally safe, some patients develop side effects, which can include mild diarrhea (which generally goes away within a few days without treatment), headaches, sedation, difficulty sleeping, vivid dreams, and loss of interest in sex.
Peppermint oil, an age-old remedy for many conditions, is recommended and used by many people who have IBS for alleviation of abdominal pain and bloating. A small research study performed nearly 30 years ago found that peppermint oil, when placed on a small strip of smooth muscle, caused the muscle to relax. This finding led to several small clinical trials of the effects of peppermint oil in patients who have IBS. Those studies noted modest improvement in some patients’ abdominal pain. Other studies, however, have not shown any improvement. An analysis of all published medical studies of peppermint oil (a meta-analysis) showed no significant improvements in abdominal pain and bloating in people who have IBS. Thus, the data from research studies, when taken as a whole, do not support the theory that peppermint oil significantly improves IBS symptoms in most patients.
Peppermint oil is a safe medication and is reasonably inexpensive. Many patients who have IBS do find that it provides some relief from their symptoms. If you decide to try peppermint oil, make sure that you buy it from a reputable health food store, and get the enteric-coated formulation. The enteric coating delays release in the GI tract. If the oil is released too soon, it is rapidly broken down in the stomach, and is of little or no value for the relief of abdominal pain. The most common side effect of peppermint oil, ironically, is heartburn. Peppermint oil can relax the lower esophageal sphincter (the smooth-muscle valve at the end of your esophagus), thereby increasing the risk that stomach acid will reflux, or regurgitate, into the esophagus.
Very few other alternative medications or treatments have been evaluated in people who have IBS. One well-designed, randomized, placebo-controlled trial found that patients who had IBS and were treated with a standard Chinese herbal formulation (a combination of more than 20 herbs) noted improvement in multiple symptoms of IBS compared to patients who had IBS and were treated with a placebo. An Ayurvedic preparation of two herbs was found to be superior to placebo in the treatment of patients who had IBS and diarrhea in a six-week, double-blind, randomized, controlled trial. Ginger and aloe (liquid) are commonly used by people who have IBS, although there are no controlled trials evaluating their efficacy. Acupuncture has given symptomatic relief to some people who have IBS. A recent placebo-controlled trial testing acupuncture’s influence on rectal sensation found no effect.
More and more people are using natural remedies and alternative treatments when conventional medications have failed to provide relief. If you elect to do so, please make sure that you bring any herbal medications (or their labels) to your next doctor’s appointment, to ensure that the medication is not dangerous or incompatible with another medication you are taking.
Maria’s story, presented at the beginning of this chapter, illustrates how difficult it can be to get relief from chronic abdominal pain. The story also reminds us that narcotics are very effective at relieving nearly every type of bodily pain. If narcotics are so good at combating pain, why not treat the abdominal pain of IBS with them?
There are several good reasons why narcotics should not be used to treat chronic or recurrent abdominal pain. (Note that the treatment of abdominal pain from cancer is a very different matter, not appropriate for discussion here.) First, narcotics are addictive. That means that the body quickly becomes used to the dose of medication initially prescribed and requires an ever-increasing amount to attain the same degree of effect. This phenomenon is called tolerance. Medically, tolerance is defined as a decrease in the effectiveness of a medication with repeated administration. That is, the body begins to “tolerate” a certain amount of the drug rather than being altered by it and thus requires more and more of the medication. This would result only in increasing expense if it were not for the many other disadvantages to taking a narcotic drug.
Narcotics have significant side effects. The most common ones are constipation, fatigue, sedation, delayed reflexes, and inability to think properly. In many cases these side effects themselves can be treated. For example, patients on narcotics may need to take additional medications every day to treat their constipation (stool softeners, milk of magnesia, Miralax, tegaserod). However, other side effects cannot be easily treated—medications are not available to improve memory or concentration or to prevent the fatigue and grogginess commonly found in patients taking narcotics.
Especially important in the case of medications to which the body becomes tolerant is the fact that overdoses of narcotics can be fatal. More disadvantages of ever-increasing doses of narcotics are that the body may become insensitive to warning signs of another medical problem and that the possibility of dangerous drug interactions may arise.
Narcotics can have significant economic side effects that most people could not endure for more than a very short time, let alone recurrently or chronically. Many patients taking narcotics find it impossible to work, because they can’t concentrate or think properly or because they cannot safely drive, work in potentially dangerous settings, or operate heavy machinery. In many kinds of jobs, people are not allowed to work if they are being treated with narcotics, because of the known problems with delayed reflexes, difficulty concentrating, and poor memory. In addition, many patients find that narcotics take away their normal motivation and desire to perform their daily tasks and chores. Thus, patients may obtain temporary relief from pain, but they may find themselves unable to live their lives.
For all of these reasons, the vast majority of health care providers believe that narcotics should not be used to treat abdominal pain in patients who have IBS. Although this may seem cruel and cold-hearted, given the severity of some patients’ pain, the side effects and potential dangers of these medications greatly outweigh the benefits for people who have IBS.
Because the options for treating abdominal pain are still somewhat limited, health care providers have turned to medications used to treat other conditions, hoping that they might improve symptoms of IBS. All of the medications discussed in this section are available only by prescription. Because they have not been specifically evaluated in patients who have IBS, their use in treating IBS is considered off-label and somewhat experimental.
Tramadol (Ultram) is a non-narcotic analgesic designed to treat acute pain after surgery or the pain of a bone fracture or other orthopedic injury. It is also occasionally used to treat chronic pain. Some patients who have IBS find it useful, but others develop prohibitive side effects of nausea and vomiting. Tramadol cannot be used at the same time as an SSRI due to the potential for a serious, although uncommon, side effect (serotonin syndrome). Theoretical concerns exist that chronic use of tramadol could be addictive, although most addiction specialists do not believe that this is true.
Phenytoin (Dilantin) and carbamazepine (Tegretol) are anticonvulsant agents used to treat people who have seizure disorders. These medications act to “quiet” the nerves involved in the transmission of pain sensation. Some people who had seizure disorders reported that their unrelated chronic pain improved while on these medications. Consequently, they are sometimes prescribed with pain relief as the primary goal. As mentioned above, these medications have not been specifically tested with people who have IBS. Thus, we do not know the likelihood of IBS pain symptoms improving with the use of these medications.
Gabapentin (Neurontin) is a newer anticonvulsant. It is similar to carbamazepine and phenytoin, and like them, it may improve pain by modulating the transmission of pain messages from the GI tract to the spinal cord and brain. Neurontin appears to have a better safety record and fewer side effects than the older anticonvulsants and is being used much more commonly to treat conditions that involve chronic nerve pain. The collective clinical experience of many gastroenterologists is that Neurontin may be a good choice for the treatment of chronic pain, if medications are required and if tricyclic antidepressants and smooth-muscle antispasmodics are not effective.
Lyrica (pregabalin), a newer medication similar to gabapentin, is now being used to treat chronic pain syndromes. It appears to help the chronic abdominal pain associated with IBS in some patients, although large studies designed to evaluate its efficacy and safety in people who have IBS have not been performed.
Duloxetine (Cymbalta) was first approved by the FDA for the treatment of depression. It is in a different class of medications, called SNRIs (serotonin norepinephrine reuptake inhibitors). It has also been shown to improve symptoms of diabetic neuropathy (the painful nerve problems in the feet and hands that many people with Type 1 diabetes have) and fibromyalgia. Some individuals who have IBS note an improvement in their pain symptoms while on duloxetine although, once again, large studies to properly evaluate the efficacy and safety of this medication in patients who have IBS have not been performed.
As mentioned throughout this book, IBS is a complicated disorder characterized by lower abdominal pain and disordered defecation (meaning constipation, diarrhea, or both). People who have IBS often have other gastrointestinal symptoms, including excess gas, bloating, distention, fecal urgency, or straining. Every patient has a different story and a different combination of symptoms that vary in frequency and intensity. Symptoms typically wax and wane in frequency and intensity, and treatment can be complicated. One symptom may require the use of one class of medications, whereas another symptom may require the use of a different class of medications. This type of treatment is not only complicated, but it also increases costs to the patient and the likelihood of medication interactions and side effects. Ideally, all of the symptoms of IBS in an individual patient would be fully treated by one medication.
For many people who have IBS and constipation, lubiprostone is very effective at relieving these “global” IBS symptoms (see Chapter 16). This medication has been on the market since 2005 and was approved for the treatment of IBS with constipation in women in 2006, so it has a long track record of safety. Linaclotide, another medication for IBS with constipation, was shown in several large research studies to improve the global symptoms of patients who have IBS and constipation. Although only recently approved (August 2012) and thus having a shorter “real world” track record, linaclotide also appears to be effective and safe. Finally, for patients who have IBS and diarrhea, alosetron has been very helpful with improving global IBS symptoms and diarrhea in women (see Chapter 17).
• Abdominal pain or discomfort is the one symptom shared by all people who have IBS and the most common reason for a patient to seek the advice of a health care provider.
• The abdominal pain of IBS may develop due to overly strong muscular contractions in the GI tract, a hypersensitive GI tract, or a heightened awareness of pain in the central nervous system.
• Relieving the abdominal pain of IBS can be challenging. Available agents include smooth-muscle antispasmodics, tricyclic antidepressants, SSRIs, and medications (alosetron, lubiprostone, and linaclotide) that focus on the multiple, global symptoms of IBS.
• Over-the-counter medications (aspirin, acetaminophen, anti-inflammatory agents) are not effective for treating abdominal pain associated with IBS.
• Narcotics should not be used to treat the abdominal pain of IBS.