A colonoscopy examines the large intestine and rectum to detect polyps and other abnormalities. For effective and accurate results, thorough bowel preparation, particularly through dietary adjustments, is necessary.
Why Diet Matters for Colonoscopy Prep
The pre-colonoscopy diet aims to ensure the colon is completely clear of solid waste. A clean colon allows the physician an unobstructed view of the lining, important for identifying and removing polyps or other issues. Food particles can obscure visibility, potentially leading to missed diagnoses or a repeat procedure.
High-fiber foods are difficult to digest, leaving residue that interferes with the examination. This undigested material can cling to colon walls, making it challenging to spot small polyps or other changes.
Foods to Avoid Before Your Colonoscopy
To achieve a clean colon, specific foods must be avoided for several days before the procedure.
Broccoli, along with other cruciferous vegetables like cabbage, Brussels sprouts, and cauliflower, should be excluded because their high fiber content can leave residue. Similarly, corn, peas, and raw vegetables are difficult to digest and can obstruct the view.
Fruits with skins or seeds, such as berries, apples with skin, and oranges, are restricted due to their fibrous nature and indigestible parts. Nuts, seeds (including those in bread or cereals), and popcorn should be avoided as they can linger and interfere with imaging. Whole grains like whole wheat bread, brown rice, and oats contain significant fiber and are not recommended.
Tough or fatty meats can also be harder to digest and leave residue. Foods containing red, blue, or purple dyes should be avoided, as these colors can be mistaken for blood. These restrictions typically begin three to five days before the procedure, with a transition to a clear liquid diet the day before.
Recommended Foods During Colonoscopy Prep
During the days before a colonoscopy, a low-fiber, low-residue diet is advised for bowel cleansing.
Allowed foods include white bread, white rice, and plain pasta, which are easier to digest. Lean, plain proteins such as chicken, turkey, fish without skin, eggs, and tofu are acceptable.
Peeled potatoes, cooked vegetables without skin or seeds (like canned green beans), and ripe, peeled fruits without seeds are suitable options. The day before the procedure, a clear liquid diet becomes necessary. This includes plain water, clear broths, clear fruit juices without pulp (e.g., apple or white grape), and clear sports drinks. Gelatin and popsicles without red, blue, or purple dyes are also permissible to maintain hydration.