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 well-meaning friends, on which foods to avoid or which supplements or medications to take, can drive IBS sufferers crazy.
Hence, 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 that were published in the American Journal of Gastroenterology.
Irritable bowel syndrome affects the large intestine due to a malfunction in the squeezing contractions of the digestive muscles, an excess production of gas, or 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 health consequences.
The panel of gastroenterologists making the new recommendations highlighted new studies pointing to dietary culprits that could be causing symptoms. While they agree that “most food-related IBS symptoms” occurred from food intolerances, only a minority of patients knew which foods actually triggered symptoms, based on studies that eliminated the potential offenders before reintroducing them to the diet.
A spate of new studies, however, have provided stronger evidence for doctors to recommend certain dietary approaches to help 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 co-author 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 the remedies provided modest -- rather than total -- relief from symptoms.
Taking soluble fiber supplements containing psyllium husk -- instead of insoluble fiber like 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 to indicate that probiotics could be helpful: Align is one brand that had modest benefits in a small clinical trial. Lembo cautioned that probiotics are very varied, and it’s hard to say which ones work best.
The researchers also reviewed a handful of clinical trials related to diets for IBS and 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 to those who stayed on them. Another trial found that 68 percent of those who reduced certain poorly digested fruit sugars following a so-called “low FODMAP diet” reported adequate control of their symptoms compared to 23 percent of those who followed their usually eating patterns.
Developed in 2005 by Australian researchers, the diet involves cutting out the FODMAP acronym of sugars -- fermentable oligosaccharides, disaccharides, monosaccharide and polyols -- that are tough to digest and get fermented by bacteria, sometimes contributing to abdominal pain, cramps, gas, and bloating. Foods with a high FODMAP include wheat, rye, onions and legumes as well as lactose in milk products, fructose, found in high-fructose corn syrup, honey and certain fruits like apples and pears, and low-calorie sweeteners like 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; foods are added back one at a time, in small amounts, to see how much an individual can tolerate before symptoms set in again.
Her 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 can be used to relieve pain, 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.