Colonoscopy involves the doctor analyzing the bowel for polyps or lesions that can become cancerous, and a special diet eliminates all solids in the bowel so the doctor can clearly see the area. If food is still in the colon, the doctor could overlook potentially harmful growths, notes Harvard Medical School.
Colon and rectal cancers are the second deadliest cancer in the United States and are the third most frequent type of cancer in both men and women. Colonoscopy is used to spot and remove small growths, either before they become cancerous or before the cancer can spread to other parts of the body. While the special diet, and the aggressive laxative treatment that accompanies it, is inconvenient and uncomfortable, the preventive benefits with regard to cancer make it worthwhile, as stated by Harvard Medical School.
Several days before the colonoscopy, patients should get fiber sources out of their diet. This includes whole grains, seeds, nuts, dried fruit and raw produce. The day before the procedure, patients may not eat any solid foods. Everything they ingest has to be clear and liquid, such as clear broths and bouillons, clear sports drinks, clear sodas and clear juices. Gelatin desserts and popsicles are technically clear liquid foods, so they are also permitted. Two hours before the procedure, all consumption of food and drink has to stop, according to Harvard Medical School.