Cracking The IBS Code

Once a largely unrecognized disorder, irritable bowel syndrome (IBS) is becoming increasingly prevalent in the United States. According to the International Foundation for Functional Gastrointestinal Disorders (IFFGD), IBS affects 10% to 15% of all Americans, and it is more prevalent in this country than either asthma or diabetes. The foundation said that it is the most common condition diagnosed by gastroenterologists and one of the most widespread disorders seen by primary care physicians.

Although there is no known cure for IBS, over the past several years, various medications that address the symptoms of this disorder have been approved for use in this country. Pharmacists can play a significant role by educating patients about IBS and counseling them regarding the correct use of medications and effective symptom management.

Symptoms of IBS may also include bloating, the appearance of mucus in the stool, an urgent need to defecate, and bowels that still feel full after defecation, Locke said. He mentioned that some people may experience other gastrointestinal symptoms, perhaps related to their stomach or esophagus, or even symptoms outside the GI tract.

IFFGD said that the mean age of IBS onset is 29 years old, and that although IBS does affect men and children, it predominantly affects women. However, David Björkman, M.D., senior associate dean of the University of Utah School of Medicine in Salt Lake City, explained that it is very hard to do studies to determine the prevalence of IBS in an entire population, because many persons with IBS do not seek care. If investigators include in their studies only persons who seek a physician's care for IBS, that population consists predominantly of women.

What causes IBS?At present, the pathophysiology associated with IBS is not well understood, said Locke. It appears to be a disorder of the enteric nervous system, which results in an alteration in bowel motility and sensation, causing patients to experience abdominal pain and an alteration in bowel habits, Björkman said.

Researchers have expressed a lot of interest in motor problems of the gut, according to Locke. He also said that they are interested in investigating visceral sensitivity and the role that communication between the gut and the brain plays in producing the symptoms characteristic of IBS. Other areas of current and future research include the role of food allergies and infection in IBS, he said. It also appears that the pathogenesis of IBS may have a genetic component, so it is conceivable that an "IBS gene" may exist. He pointed out, however, that a lot more research is necessary to determine whether such a gene actually exists.