A colonoscopy is a medical procedure used to examine the lining of the large intestine, or colon. This examination is performed using a colonoscope, a flexible tube with a camera, allowing a doctor to look for abnormalities like polyps or signs of cancer. Proper dietary adjustments are essential for a successful procedure, ensuring accurate detection of any issues.
Why Diet is Important
Dietary restrictions before a colonoscopy ensure the colon is completely clean and clear of any solid waste or residue. Any remaining stool or food material can block the doctor’s view, making it difficult to identify polyps or other concerns. A clean colon allows the gastroenterologist to have an unobstructed view of the bowel lining, which is crucial for detecting subtle changes. Inadequate preparation can lead to missed polyps or other abnormalities, potentially requiring a repeat procedure. Optimal bowel preparation is directly linked to increased polyp detection rates and a more effective examination.
Foods to Avoid
Bread, especially whole-grain varieties, is restricted before a colonoscopy due to its fiber content. High-fiber foods, such as whole-grain bread, brown rice, whole-grain pasta, nuts, and seeds, are difficult to digest and can leave residue in the colon, interfering with clear visualization. Other foods to avoid include raw fruits and vegetables, corn, popcorn, and dried fruits, as their fibrous components can cling to the colon walls. Foods and liquids with red, orange, or purple dyes are also restricted because these colors can be mistaken for blood or inflammation. Begin avoiding these high-fiber foods several days, often three to five, before the scheduled colonoscopy.
Foods and Liquids You Can Have
During the initial phase of colonoscopy preparation, typically a few days before the procedure, a low-fiber diet is recommended. This diet includes foods that are easily digestible and leave minimal residue. Examples of allowed low-fiber foods include white bread, white rice, and plain crackers. Lean proteins such as skinless chicken, fish, and eggs are generally permitted, as are well-cooked, peeled vegetables without seeds, like potatoes without skin, carrots, or green beans.
As the procedure approaches, typically the day before, the diet transitions to clear liquids only. This includes plain water, clear broths (chicken, beef, or vegetable), clear fruit juices without pulp (like apple or white grape juice), and clear sodas. Plain gelatin and popsicles, provided they do not contain red or purple dyes, are also usually allowed. Staying well-hydrated by consuming these clear liquids is important throughout this phase to support the cleansing process.