Preparation for a colonoscopy may include laxative pills, liquid laxatives, enemas or a combination of all three, according to About.com. Some doctors may also suggest a liquid diet in the days before the colonoscopy.
To prep for a colonoscopy, oral laxatives, such as a pill or liquid, are usually given to patients along with instructions for a liquid, clear diet, explains About.com. These laxatives include Dulcolax, Senakot and MiraLax. Patients usually receive the liquid laxative in a powder form, and they mix it at home. Some of these liquid laxatives, such as Golytely, require drinking up to 4 liters of water.
Enemas may also be a part of colonoscopy preparation, but they can only clean out a small part of the colon, claims About.com. If dietary changes are necessary for the colonoscopy preparation, they usually occur between one to four days before the procedure. Typically, a liquid clear diet includes chicken or beef broth, apple juice, clear soda, and gelatin, but patients must avoid red drinks, as the dye may tint the colon. Coffee and tea without milk or cream are usually fine to drink before a colonoscopy, and patients must drink plenty of water in order to feel more full and to clear the intestines out.