Managing Irritable Bowel Syndrome with Diet and Medication

Doctors are using a variety of treatment options, including antibiotics and antidepressants, to try to help people looking for relief from irritable bowel syndrome (IBS), according to research reviewed by Philip Schoenfeld, MD, associate professor of medicine and director of the training program in GI epidemiology gastroenterology at the University of Michigan School of Medicine at Ann Arbor,who spoke this week at a joint conference of the American Society for Gastrointestinal Endoscopy and the American Gastroenterological Association in Coronado, California.

By the time they turn to a specialist for help, typical patients have had numerous diagnostic tests that all turned out normal, said Schoenfeld. They’ve tried laxatives and diets with extra fiber and no lactose, as well as eliminating some foods, said Schoenfeld.

“This is my average patient,” said Schoenfeld. “Yesterday there was a pathway to my door. Patients like this are usually between 20 to 40 years old. They have cramping and bloating most days and they often frequently have overlap symptoms of dyspepsia or nausea.”

While using drugs to curb constipation and diarrhea along with dietary changes is a good initial approach to management for IBS, Schoenfeld offered additional treatment suggestions that might work for those patients still struggling with symptoms. For example, a patient who has severe IBS will not get a good response from general or vague instructions on use of constipation medicine like Miralax, he said.

“You need to give them specific guidance to say ‘I want you to start out using at least a half to a full cap of Miralax every other day,’ and then give them some guidance about how to adjust it up or down based on their symptoms.”

Use of Miralax or Imodium, for patients with diarrhea, will work on how often they go to the bathroom but not on the pain and abdominal discomfort associated with IBS, a major goal in IBS treatment, Schoenfeld said.

Epidemiologic data is conflicting about whether IBS patients are more likely to have generalized anxiety disorder compared to the rest of the population. However, Schoenfeld said that patients with IBS who have tried a host of other options before finally seeking out a gastroenterologist for subspecialty care “definitely are more likely” to be suffering from generalized anxiety disorder. “So if they get to us, yeah you can bet they are more likely to have depression or anxiety,” he said.

When prescribing antidepressants for IBS patients, the basic rule is to use a tricyclic antidepressant if the condition is diarrhea-predominant (IBS-D) and prescribe selective serotonin reuptake inhibitors (SSRI) if the patient is battling constipation (IBS-C). Schoenfeld cautioned his fellow physicians to take time to explain to patients how the drugs work on pain pathways that go from the gut to the brain to decrease or slow down activity in those pain centers.

“My real point is saying to the patient, ‘Look I’m not prescribing an antidepressant for you because I think this is all in your head. I’m prescribing it because I don’t have good medicines that treat the abdominal pain problem in your gut so I’ve got to use the medicine that works on the pain centers in the brain.”

Dr. Schoenfeld serves on advisory board of Ironwood Pharmaceuticals, Forest Laboratories, and Salix Pharmaceuticals.