Based on the present disclosure, a minimal time interval can be achieved between the last ingestion of a picosulfate composition and the performance of the colonoscopy. For example, the present disclosure is directed to a method of timing a colonoscopy procedure performed on a patient in need thereof, comprising: administering, to the patient, a picosulfate bowel composition kit according to the kit's instructions; performing the procedure less than about 4 hours after the administration of the kit.