Older treatments effective remedies for IBS

Washington -- Fiber, antispasmodics and peppermint oil are all effective therapies for irritable bowel syndrome and should be considered first-line treatments for the common but difficult to treat disorder, according to a study published online Nov. 13, 2008, in BMJ (link).

The authors recommend national guidelines on the management of IBS be updated in light of the evidence presented in their study. "These remedies are cheap, effective and, some are available over the counter and should be considered first-line treatment in primary care," said lead author Alexander C. Ford, MD, lecturer in medicine and honorary specialist registrar in gastroenterology at St. James's University Hospital in Leeds, England.

Dr. Ford's study was a meta-analysis of randomized controlled trials and was conducted for the American College of Gastroenterology, which is working on evidence-based recommendations for treating IBS. Their updated document is due out early next year, said a spokeswoman.

IBS is thought to affect as many as one in five people, making it one of the most common disorders seen by physicians. It begins before age 35 in about 50% of cases and occurs more often in women than men, according to the National Digestive Diseases Information Clearinghouse.

New medications for IBS have been plagued by safety problems and are marketed only under severe restrictions. However, one, Amitiza, or lubiprostone, was approved in April 2008 for the treatment of IBS with constipation for women 18 and older. It had been marketed since 2006 for treating constipation.

The study authors decided the time had come to review the evidence for the older treatments. To sort through the data, the researchers analyzed trials that compared each of the three remedies to placebo or no treatment. More than 2,500 adults were enrolled in the trials.

Twelve studies compared fiber with placebo or no treatment. The studies enrolled 591 patients. Surprisingly, the new analysis found that insoluble fiber, such as bran, was not beneficial, but the soluble fiber, ispaghula husk or psyllium, significantly reduced symptoms.

They also analyzed 22 studies that compared antispasmodics with placebo in 1,778 patients. Hyoscine was the most successful at preventing symptoms of IBS. The researchers suggested the treatment be used as a first-line antispasmodic therapy.

Peppermint oil, which has been shown to have antispasmodic properties, emerged as the most effective of the three agents based on four trials involving 392 patients.

Traditionally, people with IBS were advised to increase their daily intake of dietary fiber because of its potentially beneficial effects on intestinal transit time, wrote the researchers. If that failed, various types of smooth muscle relaxants and antispasmodics were used.

"The results of this study should reawaken interest in the pharmacotherapy of IBS and stimulate further research," wrote Roger Jones, professor of general practice at King's College, London, in an accompanying editorial.

He cautioned the new evidence should not detract from the need for an integrated treatment approach, which takes account of physical, psychological and social factors.

Although the trial was not designed to determine which of the three therapies was most effective, Eamonn Quigley, MD, a study author and ACG president, said he would advise antispasmodics for the short-term relief of pain and for bloating and gas. Peppermint oil "is worth trying, and fiber is really only of use in constipation."