Affecting about 12% of Americans, more often women and people younger than 45, irritable bowel syndrome (IBS) involves chronic diarrhea, constipation, or both, along with abdominal cramping. It does not alter bowel tissue or put patients at increased risk for colorectal cancer as more serious gut conditions do. It does cause pain, embarrassment, and anxiety in sufferers who must plan their activities only in places close to a restroom.
Although the FDA has approved two new drugs for treatment of IBS, severe side effects are possible. A diet developed in Australia eliminates or reduces foods that have been found to trigger symptoms. It is called “Low Fodmap,” an acronym for “fermentable oligosaccharides, disaccharides, monosaccharides, and polyols,” which are a group of sugars and other food ingredients poorly absorbed in the gut. Eating foods with low amounts of these substances helps minimize the diarrhea, gas, and bloating. Compared with a traditional American diet it also reduces the frequency of abdominal pain. More research is needed to show that this diet does not have a negative effect on gut microbes.