The Best Diet Pre-Colonoscopy

Shop for your colonoscopy prep food at least five days before your colonoscopy and plan out your daily menus.
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The worst part of a colonoscopy starts about three days before. That's when you most likely will have to start your colonoscopy prep diet to ensure that your doctor will have a clear view of the inner part of your colon and rectal area.


Shop for your colonoscopy prep food at least five days before your colonoscopy and plan out your daily menus. That way, you can focus on eating and drinking the right foods and clearing out your intestinal system.

Colonoscopy Prep Diet

According to the Colorectal Cancer Alliance (CCA), you should alter your diet starting five days before your procedure. At that time, you should stop eating foods rich in fiber as well as nuts, beans, whole grains, fruits and vegetables. First, you'll replace them with bland foods, and eventually with clear liquids. Discuss your diet with your doctor and make sure everything you plan to eat is in line with his recommendations.

The low-fiber diet for a colonoscopy helps empty your bowel. Although many colonoscopy prep instructions recommend starting three days before your procedure, CCA's Sample Six-Day Colonoscopy Prep Guide recommends cutting out high-fiber foods five days before. This is when you should also stop taking vitamin, herbal and oral iron supplements. Here's what the CCA states you should stop eating five days before your colonoscopy:

  • Any foods containing seeds, nuts or popcorn
  • Raw vegetables with a skin, seeds, corn, broccoli, cabbage, dried beans or peas
  • Whole grain bread or pasta, brown or wild rice, cereals, shredded wheat and granola
  • Fruit with skins
  • Tough meat with gristle
  • Fatty foods

Each day, you'll eat a little less food until the day before your exam, when you'll consume only clear liquids. You'll also take a series of laxatives to clear out your colon and rectal areas. This is vital to help your doctor get the best view possible so you don't have to repeat the procedure in the near future.

Read more: What Can You Eat When Preparing for a Colonoscopy?

Preventing Colon Cancer

You're focusing on the right foods to eat before a colonoscopy and undergoing the procedure because you want to avoid colon or rectal cancer. The lifetime risk of developing colon cancer is about one in 23, the CCA states. Approximately 71 percent of colorectal cancers occur in the colon and 29 percent occur in the rectum. You should get screened every 10 years starting at age 50 — and even earlier if you're at risk.

The median age for colon cancer is 68 for men and 72 for women, the CCA reports. For rectal cancer, the median age is 63 for both men and women. Colorectal cancer rates in people younger than 50 have risen in recent years, mostly among people in their 40s.

Family history and ethnicity can make a difference in who is likely to get colon cancer, the CCA reports. African Americans have colorectal cancer rates that are 40 percent higher than those of white people. Individuals with a parent, sibling or other first-degree relatives who have this disease are two to three times more likely to develop it than those with no family history.

Read more: 10 Foods Linked to Cancer You Need to Stop Eating Now

Facts About Colon Cancer

Colorectal cancers are the third most common cancer and the second most common cause of cancer-related deaths in the U.S., according to the CCA. The best way to catch colon or rectal cancer early is to have a colonoscopy, the CCA states.

When you have a colonoscopy, your doctor will probe the inside of your colon and rectal areas to see if there are any tumors or polyps, which can grow into benign or malignant tumors. Finding polyps and tumors in the earliest stages can significantly increase your chances of recovery.

Before your procedure, according to the Cleveland Clinic, you'll get a sedative and a pain reliever. Your doctor will then use a colonoscope, a long, flexible instrument about a half-inch in diameter that inspects the lining of the colon. The colonoscope is inserted through your rectum and continues through your large intestine to give the doctor a clear view of your colon. The whole process takes 30 minutes to an hour.

An article published in the October 2014 edition of the journal Gastroenterology states that up to 20 to 25 percent of colonoscopies have inadequate bowel preparation. The authors reviewed studies that involved as few as 21 people and as many as 50,000 people. Many of the studies had hundreds of participants.

Foods to Eat Before Colonoscopy

The list of foods to eat four days before a colonoscopy include solid food, but not much fiber. On day four, CCA suggests a breakfast of eggs with white toast and jam, a lunch of a turkey sandwich on white bread with avocados and baked potato chips and a dinner of grilled chicken thighs, sautéed mushrooms and white rice cooked in chicken broth. You're cutting out most fiber, but you're still eating somewhat normally.

Three days before, your colonoscopy prep diet still has you eating solid food. Here's the CCA's suggested meal plan for day three before your colonoscopy:

  • Breakfast: Greek yogurt with bananas and honey topping
  • Lunch: tuna with olive oil and lemon juice on sourdough bread, honeydew melon cubes
  • Dinner: cedar plank wild salmon (no coloring), sautéed spinach with garlic

After those first days, you may be starting to get a little discouraged, and a little tired of restricting your foods. As the Mayo Clinic points out, a clean colon is the key to a successful colonoscopy. If there's any residue in your colon, it may obscure your doctor's view of the colon and rectum during the exam.

Read more: What Can Be Eaten Before a Colonoscopy?

Two Days Before Your Colonoscopy

Two days before the procedure, you'll continue eating a low-fiber diet, but with fewer solid foods. The CCA suggests the following:

  • Breakfast: half cantaloupe with Greek yogurt and honey topping
  • Lunch: turkey sandwich on sourdough bread, honeydew melon cubes
  • Dinner: orecchiette pasta

On the day before your colonoscopy, you won't eat any solid foods. According to Kaiser Permanente, you'll need to follow a clear liquid diet.

That doesn't mean you can drink just any liquids, though. You can't have milk, cream, orange juice, grapefruit juice, tomato juice, soup other than clear broth and any frozen flavored ice pops or gelatins with red or purple dye. Also, alcoholic beverages are off-limits.

You can have frozen pops or gelatin that doesn't have red or purple dye. White cranberry juice, light-colored sports drinks, most sodas, and tea and coffee without milk, cream or lightener are all OK, according to Kaiser Permanente. Still, if you're unsure, check with your doctor. Also, you'll need to consult him about any medications you take.

Many health providers will want you to start taking a laxative sometime in the afternoon the day before your procedure. Follow the instructions on taking the laxative. It will probably take your body a good six hours to flush itself of any contents in your bowel. It's best to be home for this — and near a bathroom.

The Day of Your Procedure

About five hours before your procedure, Kaiser Permanente states you may take a second laxative dose. Kaiser Permanente recommends not drinking fluids two hours before your test, but check with your doctor on this. When it's time for your procedure, have a friend or family member drive you to the testing center.

The procedure typically lasts a half-hour to an hour, according to the Cleveland Clinic. Afterward, you'll want someone to drive you home, and you'll be advised not to drive for 24 hours. You may be hungry, and unless told otherwise, the Cleveland Clinic states you'll be allowed to eat normally. After 24 hours, you can resume most normal activities.

You probably won't need to go through this again for 10 years unless you're high-risk, according to the CCA. If you are high-risk, your doctor will let you know how often you need to be screened. You should get the results within 10 days or so, depending on the clinic.

Is This an Emergency?

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