For the 5 to 15 percent of Americans who suffer from irritable bowel syndrome, managing chronic symptoms — constipation, diarrhea, gas, and abdominal pain — can be an exercise in frustration. Contradictory advice from doctors, nutritionists, and friends, about which foods to avoid or which supplements or medications to take, can drive sufferers crazy.
So I was happy to see that the American College of Gastroenterology tried to clear up some of the confusion by issuing updated recommendations for the treatment of IBS, which were published in the American Journal of Gastroenterology.
Irritable bowel syndrome affects the large intestine and is caused by a malfunction in the contractions of the digestive muscles, an excess production of gas, or an imbalance in the amount of water entering the intestine. While symptoms can destroy a person’s quality of life, the condition — unlike ulcerative colitis, celiac disease, or other inflammatory conditions — doesn’t have life-threatening consequences.
A spate of new studies have provided stronger evidence for doctors to recommend certain dietary approaches to ease the diarrhea, bloating, or sometimes-piercing abdominal pain. “We’re not moving away from drug therapies to manage symptoms,” said Dr. Anthony Lembo, a gastroenterologist at Beth Israel Deaconess Medical Center and coauthor of the new recommendations. “But we’re also starting to recommend certain diets and supplements that have been tested in clinical trials.”
He emphasized, however, that these studies were typically small, and that the remedies provided modest relief from symptoms.
Taking soluble fiber supplements containing psyllium husk — instead of insoluble fiber such as bran — is more beneficial for alleviating alternating bouts of constipation and diarrhea, the latest research suggests, though such supplements don’t help much to relieve abdominal pain.
Evidence is building for probiotics. Lembo cautioned that probiotics are varied, and it’s hard to say which ones work best.
A handful of clinical trials related to diets for IBS found that patients following gluten-free diets to control their symptoms were more likely to have a recurrence of problems once they started eating gluten again compared with those who stayed on the diets. Another study found that 68 percent of IBS sufferers who reduced consumption of certain poorly digested fruit sugars, following a so-called “low FODMAP diet,” reported adequate control of their symptoms compared with 23 percent of those who followed their usual eating patterns.
Developed in 2005 by Australian researchers, the diet involves cutting out fermentable oligosaccharides, disaccharides, monosaccharide and polyols — represented by the acronym FODMAP — that are tough to digest and get fermented by bacteria, sometimes contributing to abdominal pain, cramps, gas, and bloating. Foods with a high FODMAP content include wheat, rye, onions, and legumes, as well as lactose in milk products, fructose — found in high fructose corn syrup, honey, and certain fruits such as apples and pears — and low-calorie sweeteners such as mannitol and sorbitol.
Following the tenets of the diet can be tricky, said Kate Scarlata, a registered dietitian in Boston who specializes in counseling patients on the low-FODMAP diet. “I recommend people learn it from a professional because the diet has lots of little nuances like which additives in processed foods to avoid,” she said. “Those who do this on their own may miss the boat on a few things and may never know if the diet can truly help manage their IBS symptoms.”
While the diet typically requires eliminating a long list of foods at first, Scarlata emphasizes that the restrictions are temporary, with foods added back gradually to determine how much an individual can tolerate before symptoms set in again.
Counseling sessions for IBS patients are covered by most health plans in Massachusetts, she said, though usually not by Medicare.
“In my experience, I would say, 75 percent of my patients feel better on this diet,” Scarlata said, but she first rules out other causes of gastrointestinal symptoms, including celiac disease, parasites, or an overgrowth of intestinal bacteria, before suggesting the low-FODMAP plan.
For some patients, over-the-counter and prescription medications can be a vital part of the IBS treatment arsenal. Anti-spasmodics and immodium can be used to relieve diarrhea and fiber supplements and laxatives can be used for constipation. Antidepressants have been found in some clinical trials to be better than placebos for abdominal pain. All of the drugs have potential side effects that need to be weighed against how well they alleviate a particular patient’s symptoms, Lembo said.
Correction: An earlier version gave an incorrect remedy for constipation. Immodium is used to treat diarrhea.