Washington, D.C. May 21, 2007 -- A new study demonstrated that the active ingredient in AMITIZA (lubiprostone), given 8 mcg twice a day, may improve symptom relief rates in adults with irritable bowel syndrome with constipation (IBS-C). These results were presented as a late-breaker at Digestive Disease Week 2007, the largest annual international meeting of digestive disease specialists.

"In this study, patients receiving lubiprostone were nearly twice as likely to achieve an overall response from symptoms of IBS-C compared to those receiving placebo," said Douglas A. Drossman, M.D., primary investigator, UNC Center for Functional GI and Motility Disorders, University of North Carolina, and the Chair of the Rome Committee. "As a result, lubiprostone may represent an important treatment for IBS-C sufferers."

IBS is a condition that affects approximately 58 million Americans and accounts for 25-50 percent of referrals to gastroenterologists. IBS-C symptoms include abdominal pain or discomfort associated with defecation or a change in bowel habits with features of disordered defecation.

Lubiprostone is a novel selective chloride channel activator that has been shown to be effective and well-tolerated in a number of well-controlled clinical trials in patients with chronic idiopathic constipation. Lubiprostone is marketed in the U.S. as AMITIZA, a 24-mcg gelcap that was approved for use for chronic idiopathic constipation in adults on January 31, 2006.

Sucampo Pharmaceuticals expects to submit a supplemental New Drug Application for IBS-C to the U.S. Food and Drug Administration by July 2007.

About the Study for IBS-C (lubiprostone 8 mcg)

In two phase III, multi-center, double-blind, randomized, placebo-controlled trials, 1,171 adults diagnosed with IBS-C (Rome II Criteria) were enrolled and received lubiprostone 8 mcg taken twice daily (783 adults) or placebo (388 adults) over a 12-week period.