Colonoscopy Diet: What to Eat the Day Before

In preparation for your colonoscopy, your doctor will prescribe a clear liquid diet, along with a laxative to completely clear the colon of stool and fluid. The colonoscopy diet, which provides some energy and maintains the body’s fluids, salts, and minerals, offers more foods and choices than you may realize. Here’s what you should know.

A colonoscopy diet consists exclusively of products that are liquid and transparent at room temperature. The fluids don’t need to be entirely clear, but you should be able to see through them. The following foods and drinks are typically allowed before a colonoscopy:

Water (mineral, sparkling, or plain)

Clear broth (beef or chicken)

Fat-free consomme´

Fruit juices (apple or white grape) without pulp

Noncarbonated, powder-based beverages, such as lemonade

Clear sports drinks or carbonated soft drinks, such as ginger ale, lemon-lime soda, or club soda (no cola or root beer)

Coffee or tea (without milk or cream)

Clear gelatin (without fruit pieces)

Plain ice pops (without fruit pieces or cream)

Fruit ices (but not red fruits)

Clear, hard candies

Salt, pepper, and sugar

Although they're liquid, the following foods are not translucent enough to be permitted on a clear liquid diet before a colonoscopy:

Milk

Cream

Milkshakes

Tomato juice

Orange juice

Grapefruit juice

Prune juice

Cream soups

Any soup other than broth

Oatmeal

Farina

Cream of wheat

Be sure to check with your doctor before starting a clear liquid diet, as he or she may have further restrictions based on your particular circumstances. For example, while cranberry juice is generally approved on a clear liquid diet, you may be advised to avoid it if you're having a colonoscopy since it can be mistaken for blood. In fact, you may need to avoid anything with red or purple coloring, including gelatin, ice pops, and hard candies.

Some people, unfortunately, may avoid having a colonoscopy thinking that they can't go without food for an entire day before the exam. But a clear liquid diet, such as the sample one described below, allows more food choices than you might think and can provide about 1,000 calories a day. You’ll need to supplement this colonoscopy diet by drinking clear liquids throughout the day to prevent dehydration.

Sample menu

Breakfast: 8 ounces of apple juice, 1 cup of gelatin (without fruit), 1 cup of coffee with sugar but no milk or cream

Lunch: 1 cup of chicken consomme´, 8 ounces of ginger ale, 1 cup of fruit ice, hot tea with sugar and lemon (no pulp)

Snack: One or two clear hard candies or a plain ice pop (without fruit pieces or cream)

Dinner: 1 cup of beef broth, 8 ounces of white grape juice, 1 cup of gelatin (without fruit), hot tea with sugar and lemon (no pulp)