answer:What your saying is logically true, but I don’t think that the doc really takes that into account. They don’t know your metabolism or body patterns, so they err on the side of completeness. They want the whole length of the colon totally empty. By the way, if they were to give you the choice drinking the foul tasting liquid or the swallowing the pills, take the pills. They accomplish the same thing – total evacuation – but the pills don’t make you gag from the fake-fruit taste.