Diet as a Treatment Option
Diet is usually the starting point for IBS treatment, Chey said. “The standard dietary recommendations, as defined by the National Institute for Health and Care Excellence Guidance for managing IBS, are reasonable and common sense — eating three meals a day, avoiding carbonated beverages, excess alcohol, and excess caffeine, and avoiding hard-to-digest foods that can be gas producing.”
A diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs), which are carbohydrates that aren’t completely absorbed in the intestines, has been shown to be effective in alleviating GI distress in as many as 86% of patients with IBS, leading to improvements in overall GI symptoms as well as individual symptoms (eg, abdominal pain, bloating, constipation, diarrhea, and flatulence).
Desmond recommends the low FODMAP program delineated by Monash University in Australia. The diet should be undertaken only under the supervision of a dietitian, he warned. Moreover, following it on a long-term basis can have an adverse impact on dietary quality and the gut microbiome. Therefore, “it’s important to embark on stepwise reintroduction of FODMAPS under supervision to find acceptable thresholds that don’t cause a return of symptoms.”
A growing body of research suggests that following the Mediterranean diet can be helpful in reducing IBS symptoms. Chey said that some patients who tend to over-restrict their eating might benefit from a less restrictive diet than the typical low FODMAPs diet. For them, the Mediterranean diet may be a good option.
Pharmacotherapy for IBS
Nutritional approaches aren’t for everyone, Chey noted. “Some people don’t want to be on a highly restricted diet.” For them, medications addressing symptoms might be a better option.
Antispasmodics — either anticholinergics (hyoscine and dicyclomine) or smooth muscle relaxants (alverine, mebeverine, and peppermint oil) — can be helpful, although they can worsen constipation in a dose-dependent manner. It is advisable to use them on an as-needed rather than long-term basis.
Antidiarrheal agents include loperamide and diphenoxylate.
For constipation, laxatives (eg, senna, bisacodyl, polyethylene glycol, and sodium picosulfate) can be helpful.
Desmond noted that the American Gastroenterological Association does not recommend routine use of probiotics for most GI disorders, including IBS. Exceptions include prevention of Clostridioides difficile, ulcerative colitis, and pouchitis.
Targeting the Gut-Brain Relationship
Stress plays a role in exacerbating symptoms in patients with IBS and is an important target for intervention.
“If patients are living with a level of stress that’s impairing, we won’t be able to solve their gut issues until we resolve their stress issues,” Desmond said. “We need to calm the gut-microbiome-brain axis, which is multidimensional and bidirectional.”
Many people — even those without IBS — experience queasiness or diarrhea prior to a major event they’re nervous about, Chey noted. These events activate the brain, which activates the nervous system, which interacts with the GI tract. Indeed, IBS is now recognized as a disorder of gut-brain interaction, he said.
“We now know that the microbiome in the GI tract influences cognition and emotional function, depression, and anxiety. One might say that the gut is the ‘center of the universe’ to human beings,” Chey said.
Evidence-based psychological approaches for stress reduction in patients with IBS include cognitive behavioral therapy, specifically tailored to helping the patient identify associations between IBS symptoms and thoughts, emotions, and actions, as well as learning new behaviors and engaging in stress management. Psychodynamic (interpersonal) therapy enables patients to understand the connection between GI symptoms and interpersonal conflicts, emotional factors, or relationship difficulties.
Gut-directed hypnotherapy (GDH) is a “proven modality for IBS,” Desmond said. Unlike other forms of hypnotherapy, GDH focuses specifically on controlling and normalizing GI function. Studies have shown a reduction of ≥ 30% in abdominal pain in two thirds of participants, with overall response rates up to 85%. It can be delivered in an individual or group setting or via a smartphone.
Desmond recommends mindfulness-based therapy (MBT) for IBS. MBT focuses on the “cultivation of mindfulness, defined as intentional, nonjudgmental, present-focused awareness.” It has been found effective in reducing flares and the markers of gut inflammation in ulcerative colitis, as well as reducing symptoms of IBS.
Chey noted that an emerging body of literature supports the potential role of acupuncture in treating IBS, and his clinic employs it. “I would like to see further research into other areas of CAM [complementary and alternative medicine], including herbal approaches to IBS symptoms as well as stress.”
Finally, all the experts agree that more research is needed.
“The real tragedy is that the NIH invests next to nothing in IBS, in contrast to inflammatory bowel disease and many other conditions,” Pimentel said. “Yet IBS is 45 times more common than inflammatory bowel disease.”
Pimentel hopes that with enough advocacy and recognition that IBS isn’t “just stress-related,” more resources will be devoted to understanding this debilitating condition.
Desmond is the author of a book on the benefits of a plant-based diet. He has also received honoraria, speaking, and consultancy fees from the European Space Agency, Dyson Institute of Engineering and Technology, Riverford Organic Farmers, Ltd., Salesforce Inc., Sentara Healthcare, Saudi Sports for All Federation, the Physicians Committee for Responsible Medicine, The Plantrician Project, Doctors for Nutrition, and The Happy Pear.
Pimentel is a consultant for Bausch Health, Ferring Pharmaceuticals, and Ardelyx. He holds equity in and is also a consultant for Dieta Health, Salvo Health, Cylinder Health, and Gemelli Biotech. Cedars-Sinai has a licensing agreement with Gemelli Biotech and Hobbs Medical.
Chey is a consultant to AbbVie, Ardelyx, Atmo, Biomerica, Gemelli Biotech, Ironwood Pharmaceuticals, Nestlé, QOL Medical, Phathom Pharmaceuticals, Redhill, Salix/Valeant, Takeda, and Vibrant. He receives grant/research funding from Commonwealth Diagnostics International, Inc., US Food and Drug Administration, National Institutes of Health, QOL Medical, and Salix/Valeant. He holds stock options in Coprata, Dieta Health, Evinature, FoodMarble, Kiwi Biosciences, and ModifyHealth. He is a board or advisory panel member of the American College of Gastroenterology, GI Health Foundation, International Foundation for Gastrointestinal Disorders, Rome. He holds patents on My Nutrition Health, Digital Manometry, and Rectal Expulsion Device.
A version of this article appeared on Medscape.com.
