A few days prior to a colonoscopy, starting a diet low in fiber and avoiding whole grains, seeds, nuts and raw fruits and vegetables are recommended, according to Harvard Health Publications. The day before the colonoscopy, a clear liquid diet should be consumed.
A clear liquid diet involves consuming items such as clear broth, black coffee, clear soft drinks, Jell-O and clear juices such as apple or white grape, notes Harvard Health Publications. Liquids that contain red, blue or purple dye should be avoided. Patients are typically allowed nothing to eat or drink after midnight the night before their colonoscopy, according to Mayo Clinic. The exact instructions may vary based on doctor's preference and the time of the colonoscopy.
In addition to consuming a special diet, patients are prescribed a bowel preparation to take before their colonoscopy, which may include enemas, oral tablets or liquids, states Mayo Clinic. The goal of the bowel prep is to completely empty the contents of the colon, resulting in high-volume diarrhea, explains Harvard Health Publications. During the bowel prep, patients are advised to clear their schedule, wear loose clothing and remain near a bathroom. Having medicated wipes and a skin-soothing cream available are also recommended.