On August 23, 2004, the FDA approved Zelnorm (Novartis Pharmaceuticals,East Hanover, NJ) for the treatment of chronic idiopathic constipation in maleand female patients younger than 65 years of age. This makes Zelnorm the firstFDA-approved prescription medication for use in patients with chronic constipation.Other available agents are indicated only for use in patients with occasionalconstipation. The FDA's decision was based on efficacy and safety datafrom 2 of the largest and longest randomized, double-blind, placebo-controlled,multinational, phase 3 trials conducted in chronic constipation. The two 3-month trials included more than 2600 male and female patients. Compared withplacebo, Zelnorm was found to significantly increase the frequency of completespontaneous bowel movements and to provide relief of the symptoms of chronicconstipation for which patients seek help most often, including straining, hardstool, sense of incomplete evacuation, infrequent defecation, bloating, andabdominal discomfort.