Colonoscopy preparation

Dear Ask The Doctor: I am scheduled for a colonoscopy on Friday. I had a sandwich today (Sunday) with multigrain bread. Will this be a problem or should will I be O.K. starting the low fiber diet from this afternoon forward?

Dear Andre: Bowel preparation is required prior to a colonoscopy so that the large bowel is clear of all faecal material allowing the bowel wall to be visualized through a camera lens. It is therefore important to follow the preparation rigorously otherwise the investigation may be inadequate, if the entire large bowel cannot be viewed. I would advise continuing strictly to the bowel preparation guidelines, or if this is not possible rescheduling the colonoscopy, for a future date.