While patients must follow a clear liquid diet in preparation for their colonoscopy, after the procedure, they return to a normal diet, according to WebMD. The clear liquid diet, along with the laxatives the doctor prescribes, ensures the colon is clean for a successful procedure.
If the doctor removes a polyp during the colonoscopy, he may recommend the patient modify his diet temporarily, explains Mayo Clinic. Feeling bloated and needing to pass gas after the procedure is normal. Walking is helpful for reducing the pressure. The first bowel movement after the procedure sometimes contains a small amount of blood, which is not a cause for concern; however, patients who continue to pass blood or have a fever should contact their doctor.
Any residue in the colon during the procedure may obscure the doctor's view, states Mayo Clinic. The clear liquid diet prior to the procedure includes carbonated beverages, broth, water and tea. However, the patient should avoid milk, cream and any red-colored drinks. After midnight prior to the procedure, the doctor may instruct the patient to stop eating or drinking anything. If the doctor has concerns about the view of the colon, he sometimes advises a repeat procedure. In some cases, doctors advise a barium enema and virtual colonoscopy if there is an obstructed view.