Considered subjects will be screened to determine eligibility for entry into the study. The Screening Visit must take place at least 14 days, but not more than 21 days, before the planned date of study entry (randomization and administration of the first dose of study drug on Study Day 1). The baseline evaluation of gastric emptying must be scheduled at least 7 days (in the U.S.) and 10 days (in Europe) before the Day 1 Visit. Subjects will answer questions relating to their gastroparesis symptoms in an electronic diary (like a palm pilot) beginning on the first day of the screening period.