Irritable Bowel Syndrome
Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that sometimes causes significant discomfort even though it is not a serious health threat.
The cause of IBS remains unknown. IBS is not related to inflammatory bowel diseases, such as Crohn’s disease or ulcerative colitis.
What are the symptoms of IBS?
Typical symptoms include abdominal bloating and soreness, gas, and alternating diarrhea and constipation. People with IBS are more likely than others to have backaches, fatigue, and several other seemingly unrelated problems.
Dietary changes that may be helpful for irritable bowel syndrome
Several trials report that food sensitivities occur in only a small percentage of people with IBS.1 2 3 However, a leading researcher in the field claims at least 3.5 ounces of the offending food need to be consumed at frequent intervals to provoke IBS symptoms,4 and the amount of test foods used in these studies was generally less than this amount. Therefore, inadequate quantities of food may have affected the outcomes of these trials. Other trials have reported that most IBS sufferers have food sensitivities, and that gas production and IBS symptoms diminish when the offending foods are discovered and avoided.5 6 7 8 Some researchers report that problem foods need to be eaten at every meal for at least two days to evaluate the potential of food sensitivity.9
Researchers have found that standard blood tests used to evaluate allergies may not uncover food sensitivities associated with IBS, because IBS food sensitivities may not be true allergies.10 11 The only practical way to evaluate which foods might trigger IBS symptoms is to avoid the foods and then reintroduce them. Such a procedure requires the guidance of a healthcare practitioner. Attempts to find and avoid problem foods without professional help may fail and may aggravate symptoms.
Preliminary evidence suggests that some people with IBS have greater trouble absorbing the sugars lactose (as found in milk), fructose (as found in high concentration in fruit juice and dried fruit), and sorbitol (as found in some dietetic candy) than do healthy people.12 In this report, restricting intake of these sugars led to reduction in symptoms in 40% of people with IBS.
Limited research has suggested that fiber might help people with IBS.13 14 However, most studies find that IBS sufferers do not benefit by adding wheat bran to their diets,15 16 17 18 and some people feel worse as a result of wheat bran supplementation.19 The lack of positive response to wheat bran may result from a wheat sensitivity,20 which is one of the most common triggers for food sensitivity in people with IBS.21 Rye, brown rice, oatmeal, barley, vegetables, and psyllium husk are good sources of fiber and are less likely to trigger food sensitivities than is wheat bran. Except for psyllium, little is known about the effects of these other fibers in people with IBS.
Nutritional supplements that may be helpful for irritable bowel syndrome
Double-blind research has shown that avoidance of lactose (present in milk and some other dairy products) by people with IBS who are also lactose intolerant will relieve IBS symptoms.22 Alternatively, lactase enzyme may be used prior to consuming milk. Several different lactase products are commercially available and the amount needed depends on the specific preparation being used.
In one trial, women with IBS who experienced worsening symptoms before and during their menstrual period were helped by taking enough evening primrose oil (EPO) to provide 360–400 mg of gamma linolenic acid (GLA) per day.23 In that trial more than half reported improvement with EPO, but none was helped in the placebo group. The effects of EPO in other groups of IBS sufferers have not been explored.
A preliminary trial investigated the effectiveness of grapefruit seed extract in people with eczema and symptoms of IBS.24 Participants received either 2 drops of a 0.5% oral solution of grapefruit seed extract twice daily or 150 mg of encapsulated grapefruit seed extract three times daily. After a month, IBS symptoms had improved in 20% of those taking the liquid, while all of the patients taking capsules noted definite improvement of constipation, flatulence, abdominal discomfort, and night rest. These results need confirmation in double-blind trials.
Are there any side effects or interactions with irritable bowel syndrome?
Refer to the individual supplement for information about any side effects or interactions.
Herbs that may be helpful for irritable bowel syndrome
Some people with IBS may benefit from bulk-forming laxatives. Psyllium seeds (3.25 grams taken three times per day) have helped regulate normal bowel activity in some people with IBS.25 Psyllium has improved IBS symptoms in double-blind trials.26 27
In the intestinal tract, peppermint oil reduces gas production, eases intestinal cramping, and soothes irritation.28 Peppermint oil has been reported to help relieve symptoms of IBS in two analyses of controlled trials.29 30 Evidence supporting the use of peppermint oil has come from double-blind trials that typically have used enteric-coated capsules that supply 0.2–0.4 ml of peppermint oil taken three times per day.31 32 33 Some trials have found peppermint oil ineffective.34 35 The reason for these conflicting findings remains unclear.
The combination of 90 mg of peppermint oil plus 50 mg of caraway oil in enteric-coated capsules taken three times per day led to significant reduction in IBS symptoms in a double-blind trial.36 In a similar trial, capsules that were not enteric-coated were as effective as enteric-coated capsules.37 The same combination has compared favorably to the drug cisapride (Propulsid®) in reducing symptoms of IBS.38 The purpose of enteric coating is to protect peppermint oil while it is passing through the acid environment of the stomach.
Whole peppermint leaf is often used either alone or in combination with other herbs to treat abdominal discomfort and mild cramping that accompany IBS. The combination of peppermint, caraway seeds, fennel seeds, and wormwood was reported to be an effective treatment for upper abdominal complaints in a double-blind trial.39
Chamomile’s essential oils have eased intestinal cramping and irritation in animals.40 Chamomile is sometimes used by herbalists to relieve alternating bouts of diarrhea and constipation, though research has yet to investigate these effects. This herb is typically taken three times per day, between meals, in a tea form by dissolving 2–3 grams of powdered chamomile or by adding 3–5 ml of herbal extract tincture to hot water.
A standardized Chinese herbal combination containing extracts from 20 plants (including wormwood (Artemisia absinthium),ginger, bupleurum, schisandra, and dan shen (Salvia miltiorrhiza) reduced IBS symptoms.41 In that double-blind trial, people were given five capsules of the herbal combination three times per day.
Are there any side effects or interactions with irritable bowel syndrome?
Refer to the individual herb for information about any side effects or interactions.
Holistic approaches that may be helpful for irritable bowel syndrome
IBS sufferers have increased sensitivity to rectal pain that has been linked to psychological factors.42 Stress is known to increase symptoms of IBS.43 Reducing stress or practicing stress management skills have been reported to be beneficial. In one trial, psychotherapy and relaxation combined with conventional treatment were more effective than conventional treatment alone in two-thirds of people with IBS.44 Hypnosis for relaxation has dramatically and consistently relieved symptoms of IBS in some people.45 46 47
Traditional Chinese Medicine (TCM), which uses acupuncture and Chinese herbal therapies, has been reported to be helpful in the treatment of IBS,48 although no formal research has evaluated this claim.