A colonoscopy is a common procedure that detects and prevents colon cancer, along with other gastrointestinal issues. To receive accurate results, all patients must follow a strict diet including specific foods to avoid before your colonoscopy. This diet includes a list of recommended and restricted foods and generally starts three days before the procedure. Proctologists may also request you follow a liquid-only diet one day before your procedure.
Understanding and following these restrictions means a smoother and more comfortable colonoscopy experience. It also ensures your proctologist or gastroenterologist can evaluate the colon properly and effectively. Colonoscopies detect colon polyps before they progress into cancer, so read closely on how to prepare for this potentially life-changing procedure.
What is the Colonoscopy Prep Diet?
Proctologists and gastroenterologists across the board recommend a low-fiber diet during the colonoscopy prep. Year-round fiber is your friend– except when you have a colonoscopy on your calendar. In addition to aiding digestion, one of fiber’s main roles is to make the stool bulky so that food waste can pass through the intestine at just the right speed.
The colonoscopy prep diet wants to avoid this…temporarily. A low-fiber diet is a low-residue diet that results in smaller bowel movements and less residue in the colon. This makes it easier for the bowel prep solution to clear everything out. On the contrary, high-fiber foods leave more undigested material in the colon obscuring the proctologists view.
A low-fiber diet also helps the laxative pill or solution you’ll have to take work its magic. During the colonoscopy prep period, the point is to stop your digestive system from producing solid stool. This way, the laxatives can effectively work on emptying the bowels, instead of competing with unnecessary material.
When patients ask me, “What not to eat before a colonoscopy,” the answer often surprises them. There are many foods to avoid that are unknown to the general public, such as those with certain colors. While specific instructions will vary on your individual medical needs, typically a proctologist will recommend you:
- Consume only clear liquids, such as water, broth, clear juices, and tea, the day before and the day of the colonoscopy
- Avoid solid foods, in particular nuts, seeds, granola, whole grain, and rice
- Adjust medications. This may include blood thinners or iron supplements, but always seek individual guidance from your doctor.
- Undergo a colon cleanse if recommended. A colonoscopy cleanse is different from trendy “wellness” treatments.
- Stay hydrated. Drink at least 8 glasses a day leading up to your colonoscopy and incorporate electrolyte beverages.
It should go without saying, but a colonoscopy is not the time to ‘wing it’. I routinely tell my patients that my bowel preparation recommendations are like military instructions. Pretend you are a soldier and obey orders unquestioningly. Don’t skip or change anything.
What Food and Beverages to Avoid Before Your Colonoscopy
Three Days Before Colonoscopy
Certain foods should be avoided three days before a colonoscopy so that your leftover theater popcorn doesn’t show up on my screen and block my view of any colon polyps that could spell trouble for you and your health.
Alongside popcorn, avoid high-fiber foods such as legumes, wholegrain bread, nuts, seeds, fresh fruit (especially those with seeds or skin), raw vegetables (and corn or peas in any form), cereals, and granola. Also, stop drinking alcohol three days before a colonoscopy. Alcoholic beverages dehydrate the body, which interferes with its effectiveness. Pulpy fruit juice is also a no-go.
Two Days Before Colonoscopy
Two days to go! Continue avoiding the foods above and sticking to the rules diligently. You’ll make your proctologist (think of them as the military commander in this case) proud and make their job much easier. If you’re stuck for food ideas, the following options are generally okay a few days before a colonoscopy: cheese, yogurt, white flour bagels, lean meats like chicken and turkey, cooked vegetables like peeled carrots, and mashed potatoes without skin.
The Day Before Colonoscopy
It’s now time to stop eating solid foods altogether and switch to a liquid-only diet. Liquids should be clear, in both color and texture. This means no pulpy fruit juices. Red or purple beverages must also be avoided as they stain the colon and give off a blood-like appearance, which can cause false alarms and lead to inaccurate results.
There are still plenty of clear liquids allowed, including:
- Electrolyte drinks: Gatorade and Powerade beverages are recommended as they replace lost fluids. Choose the yellow flavor.
- Lemonade: Diabetic and non-diabetic options are allowed, including Country Time Lemonade, 7-Up, Spite, and Ginger Ale.
- Water and Coconut Water
- Tea or Coffee: However, only in the morning and do not add milk or milk substitute.
- Soup broth: Only chicken bouillon is allowed. Bone broth, rice, noodles, or vegetable soups are not allowed.
As always, your safest bet will be water. Please note that Jello is not considered a clear liquid and cannot be consumed before a colonoscopy.
The Importance of Colon Cleansing
In the lead-up to your colonoscopy, your doctor will request that you consume a colon-cleansing solution. This will flush out any residual matter that could block the view during the procedure. A clean colon means your proctologist has the best view to scan for hidden signs of colon cancer, and if necessary, remove precancerous colon polyps.
Colon Cleaning Solutions
Colon cleansing solutions can be prescribed by your health care provider or available for over-the-counter purchase. At Thousand Oaks Proctology, I recommend patients consume the MiraLAX preparation formula. This combination of electrolytes and MiraLAX laxative powder softens stool and stimulates bowel movements.
Follow your doctor’s instructions on how to mix and drink the solution. It’s far from the most delicious medicinal cocktail, but you must finish the whole mixture…and keep it down! Otherwise, you may have to reschedule the colonoscopy.
Laxatives
Patients may also be instructed to consume additional laxatives to encourage bowel movements further. Laxatives come in the form of pills, powders, or liquids. At Thousand Oaks Proctology, I recommend patients take Dulcolax suppositories which are available over-the-counter. These tablets are inserted directly into the rectum. The method of taking each laxative medication will vary, so confirm with your doctor about specific instructions and the schedule leading up to your colonoscopy.
Taking any laxative or colon-cleansing solution can lead to dehydration. Keep hydrated, monitor your bowel movements, and don’t stray too far from the bathroom. Contact your doctor if you ever feel dizzy, weak, or pass dark urine.
How to Make the Colon Prep Diet Easier on Your Body
Colonoscopies aren’t always pleasant. While most of my patients breeze through the colonoscopy prep period, some feel anxious about accidentally doing the wrong thing. With years of experience helping patients feel comfortable throughout the colonoscopy process, from start to finish, here are my top tips:
- Plan ahead and stock up on the recommended clear liquids
- Keep busy if you are hungry or craving your favorite banned snacks
- Soothe any cramps with a heating pad
- Research “What not to eat before a colonoscopy” and meal prep the allowed colonoscopy foods
- Focus on the end goal–peace of mind and a better fight against colorectal cancers
Remember, the clear liquid diet is temporary and essential for preparing your body before the colonoscopy procedure. Stay focused, stay hydrated, and reach out for support when needed – the team at Thousand Oaks Proctology is here for you. Contact us today.