The present invention is directed to a method for treating chronic constipation in a subject in need of such treatment comprising administering to the subject a dosage formulation comprising a therapeutically effective amount of acarbose, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable ingredient to control the release of the acarbose, wherein following administration, the dosage formulation releases the acarbose distal to the gastrointestinal sites at which acarbose is absorbed.