 Study period Estimated date of first patient enrolled: January 2010 Study design This is a single-center, randomized, parallel group, double-blind, placebo-controlled, dose response, pharmacodynamic and pharmacokinetic study evaluating the effects of A3309 on gastric, intestinal and colonic transit in patients with functional constipation. Doses of 10 or 20 mg A3309 or matching placebo will be administered orally once daily for fourteen 14 consecutive days. 