Preparing for a Colonoscopy is Easier Than You Think

The 3-day prep for one of the most lifesaving cancer screenings

You may have heard that preparing for a colonoscopy is the hardest part. However, the instructions aren’t too bad.

A colonoscopy is the only way to screen and prevent colorectal cancer. Having a clean colon makes it easier for the gastroenterologist to see if there are any abnormalities or polyps. If the specialist sees polyps, they can remove them while they are doing the colonoscopy, preventing cancer from developing.

When you go to your colonoscopy consultation, you will receive instructions on how to prepare. Here are some general instructions to give you an idea of what to put on your grocery list. Preparation includes adopting a low-fiber diet by choosing foods that make bowel movements easier and do not cause constipation.

Day 1 of Prep

Cut back on some foods, including nuts or seeds, even popcorn, three days before your procedure. You may eat tender meat such as chicken or fish, but avoid tough meat and fatty foods. Do not eat whole grains, including oatmeal, cereal, granola, and shredded wheat. Instead, incorporate white bread, white rice, skinless potatoes, and pasta into your diet. Raw vegetables and fruit should be avoided, especially those with skin. Say no to broccoli, corn, beans, peas, and cabbage. Your gastroenterologist may advise you to stop taking vitamins and medications until after your colonoscopy.

Don’t forget to kick off your cleanse by hydrating during the day and drinking around eight ounces of water each hour.

The Eve of the Colonoscopy

The night before, you will have medication you need to take. Stay away from solid foods and alcohol. Instead, drink clear liquids like clear broth, black coffee or tea without cream, and clear juice like apple or white grape. You can drink clear soft drinks and sports drinks that replace electrolytes. You can even have gelatin and popsicles. Do not drink red or purple fruit juices, including prune juice, and don’t drink smoothies, milk, or other dairy products. Stick to transparent liquids.

Later in the evening, you will start taking the prep solutions your gastroenterologist prescribed to help boost your colon cleanse. The exact instructions on what to consume and when will be provided by your physician, but it is standard for patients to drink two to four liters of an oral liquid.

Colonoscopy Day                                                                

If you follow this general guide and your gastroenterologist’s instructions, your stool should be a yellow or clear liquid on the morning of your colonoscopy. Do not eat, drink, or consume any substance (cigarettes, e-cigarettes, or marijuana) at least three hours before the colonoscopy. Also, avoid chewing gum or candy. Your gastroenterologist may want you to follow additional instructions depending on your health.


Colonoscopies require a referral to a gastroenterologist. If you need a primary care physician, McLaren has doctors accepting new patients across the state. Visit to find a new provider. If you are in the Detroit, Farmington Hills, or Roseville areas, call 1-800-KARMANOS or visit to schedule your colon screening consultation.