可能是泻药距肠镜的间隔太长

• Six hours before your appointment: Drink the second dose of the prep. The American Gastroenterological Association and American College of Gastroenterology recommend the split dose because it cleans the colon more thoroughly. Even after a thorough cleansing, your stomach and pancreas are still making fluids, which flow into the colon. "The more time that elapses after you take the prep, the more likely you are to have fluid in your colon," Dr. Cheney explains.