Colonoscopy Prep Questions and Answers

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It’s OK to have hesitations about getting a colonoscopy, but it’s nothing to be feared. Colon cancer, which can be detected through regular screenings, is what you should worry about. Colorectal cancer is the second leading cause of cancer deaths in the United States, leading to almost 50,000 deaths every year.

Routine testing is recommended for people age 50 and older who have a normal risk of colon or rectal cancer. Your doctor may recommend earlier or more frequent testing if you have a higher risk.

Fortunately, colon cancer is one of the most preventable types of cancers. The number of colon cancer diagnoses has decreased over the past decade thanks to awareness, prevention and routine colonoscopies. Flush away your fears about that upcoming colonoscopy and get your questions answered!

Why do I Need a Colonoscopy? 

A colonoscopy is a crucial step to catching colon cancer early. In many cases, colon cancer does not cause noticeable symptoms until the disease has advanced. Recent statistics show that regular colonoscopies could prevent nearly 60 percent of deaths from colon cancer. A colonoscopy can detect a polyp, a growth of cells on the lining of the colon, before it becomes cancerous. Your doctor can remove the polyp, stopping cancer before it even starts.

Colonoscopies can check for a variety of symptoms and their causes:

  • Blood in stool or rectal bleeding
  • Dark or black stools
  • Diarrhea
  • Anemia
  • Unexplained weight loss
  • Abdominal pain

Colonoscopy Prep: Food & Drink

What is a Clear Liquid Diet? 

One or two days before your colonoscopy, you’ll be instructed to stop eating solid foods and drink only clear liquids. However, you’re not just stuck with water on those days. You don’t even have to give up your morning coffee! Some drinks and foods that qualify as clear liquids are clear, but some aren’t:

  • Water (plain, carbonated or flavored)
  • Tea
  • Coffee
  • Sports drinks
  • Fruit-flavored beverages like lemonade
  • Carbonated drinks, including dark beverages like root beer or cola
  • Flavored broths
  • Flavored ice pops
  • Jell-O
  • Hard candy such as lemon drops or mints

Be sure to avoid anything colored red or purple, like grape soda or cherry Jell-O. The food dye can cause misinformation during the colonoscopy. The exact diet instructions will vary, so consult with your doctor.

A clear liquid diet leaves no residue in the intestines or the stomach, giving the doctor a better look at the lining of the colon. It will also help you stay hydrated, which will help you recover faster after the procedure.

Can I drink anything other than water while I'm prepping for the colonoscopy?

Yes! It is important that you drink a variety of allowed clear liquids to avoid the possibility of becoming nauseated and dehydrated. Clear liquids include: apple and white grape juice or other non-citrus juices without pulp, Gatorade, ginger ale, diet or regular 7-Up, Sprite or colas, Kool Aid, water, clear broth, Popsicles, hard candies without filling. Also included in a clear liquid diet is black coffee or tea without cream or powdered creamer and jell-O without added fruit (no red/purple coloring). You may drink clear liquids up until 2 hours before your procedure.

Why can’t I drink or consume anything red or purple during my clear liquid diet?

When you consume something red or purple such as red jell-O, it can stain the colon or appear to be blood. To help ensure an accurate exam, these liquids should be avoided.

Can I chew gum during the prep?


Can I have sugar in my coffee/tea during my clear liquid diet?

Yes. You may use sugar or sugar substitutes in your drinks during your clear liquid diet.

Can I have cream in my coffee/tea?

No. Avoid all dairy products including milk, cream and powdered creamer.

Can I drink alcoholic beverages during the prep?

Alcoholic beverages can cause dehydration, so we strongly suggest you do not drink alcoholic beverages during your bowel prep.

Can I have soup during my clear liquid diet?

You can only have broth. You may not have noodles, meat or vegetables.

Why can’t I eat popcorn, nuts or seeds a week before my procedure?

The hulls from popcorn and some nuts and seeds can stay in the colon for days. During your procedure the hulls can appear to be growths in the colon. Popcorn hulls, small seeds/nuts can also clog the suction channel of the scope which could make the scope inoperable and have to terminate the procedure.

When can I eat after my procedure?

Generally, you can eat immediately after your procedure. Occasionally, there is mild nausea from the sedative medications. You may not have a full appetite until the following day.

Colonoscopy Prep: Medications

Can I take other medications before the procedure?

Yes, except the ones you were told to hold/stop by the doctor or nurse. Generally, you should take prescribed medication, as directed, both on the preparation day and on the day of the procedure. However, you must not take anticoagulants (blood thinners) for at least 4-7 days prior to the procedure. These include Coumadin, Plavix, Xarelto, vitamin E, ibuprofen and other NSAIDs. If you are on any of these medicines, please be sure to let us know well in advance of the procedure. Aspirin can usually be continued.

Do I need antibiotics before the procedure?

No, In general, most patients do not require antibiotics prior to a colonoscopy. Even patients with artificial knees/hips, mitral valve prolapse, pacemakers, and artificial heart valves DO NOT NEED antibiotics.

I accidentally took ibuprofen/NSAIDs or aspirin, will my procedure need to be rescheduled?

In general no, but call the doctor to be sure. These medicines thin the blood and make it a little riskier for bleeding.

I am diabetic. What should I do about my diabetes medication?

In general, take half the usual dose of diabetes medicines the day before the procedure while you are on clear liquids and prepping. Don’t take any diabetes medicine the morning of the procedure. You can resume your diabetes medicine after the procedure once you are ready to start eating again. If you have any questions about this, call the physician that manages your diabetes and tell them of your prep. That physician should determine how to adjust your medication.

Can I take my anti-anxiety medications the morning of my procedure?

Yes. You may take your anti-anxiety medications with a small sip of water.

Colonoscopy Prep: Bowel Prep and Laxatives

What is a Bowel Preparation Drink? 

Are you worried about the dreaded colonoscopy prep drink? Don’t be! Fortunately, today’s bowel preparation drink is much easier to drink than it used to be. Patients can now choose half-gallon options, instead of a full gallon, so they can split up the dose. Many doctors are now allowing patients to drink half the night before the colonoscopy and half the morning of, making it a little easier.

This drink acts as a laxative, which will help clear out the bowels. Ask your doctor if you can add flavored drink crystals like Crystal Light or lemon juice to the solution. You may also find it easier to drink the solution if you chill it in the refrigerator first.

How long will it take to complete my bowel prep?

The entire prep can take approximately four to eight hours. You should plan to be near a restroom during this period.

I already have diarrhea before starting my prep, do I still have to take all of the laxatives?

Yes. You must follow the preparation instructions given to you. Your colon is approximately 5 feet long and must be completely emptied to help ensure an accurate and thorough exam. If the colon prep is not adequate, the doctor can miss polyps or other important things in your colon.

I am very thin. Do I still have to take all of the laxatives?

Yes. You must follow the preparation instructions given to you. Your colon is approximately 5 feet long and must be completely emptied to help ensure an accurate and thorough exam. If the colon prep is not adequate, the doctor can miss polyps or other important things in your colon.

I seem to be all cleaned out but I haven’t finished my laxatives, do I have to finish them?

Yes. You must follow the preparation instructions given to you. Your colon is approximately 5 feet long and must be completely emptied to help ensure an accurate and thorough exam. If the colon prep is not adequate, the doctor can miss polyps or other important things in your colon.

I feel nauseous while I'm drinking the colon prep. What should I do?

You can take a short break from drinking the laxatives. Try drinking ginger ale or another clear liquid or sucking on candy to help settle your stomach. Continue your prep when the feeling has subsided.

I started my laxatives and I haven’t had a bowel movement yet. What should I do?

Some patients have a bowel movement immediately after starting the laxatives and for others it may take 2 hours or longer. Continue drinking clear liquids and following your bowel prep instructions. Patients with a history of chronic constipation may need more prep than usual to clean out the colon. If your stools are not clear yellow when finished, call or come to the hospital a couple hours earlier than your scheduled time, so you can drink extra prep.

I finished all the prep and have had several bowel movements but I’m still not cleaned out. What should I do?

Continue drinking lots of clear liquids. If the stools don’t turn clear yellow, you will need to come to the hospital 2 hours before your scheduled arrival time to drink more prep.

Colonoscopy Prep: What to Expect Before and After

Before Your Colonoscopy

Can I use cream during my prep to avoid anal irritation?

Yes. You may apply Desitin, A & D ointment, Vaseline or any other cream to the anus during the prep.

Can I smoke during the prep?


Can I brush my teeth the morning of my procedure?


Can I have a colonoscopy if I am having my menstrual period?


After Your Colonoscopy

How long will the colonoscopy take?

The entire procedure usually takes 30 minutes or less. You should plan to be at the facility for approximately 2 - 3 hours. The amount of time may vary from patient to patient, depending on how much sedation is needed and how you feel afterwards.

Will the procedure hurt?

You will be given sedation during the procedure to help you stay comfortable. You may experience some cramps and discomfort briefly during the exam.

Will I be asleep during the procedure?

The goal of the sedation given during the procedure is to make you drowsy and keep you comfortable but still be slightly awake so you can breath on your own and roll over if needed.

What is colonoscopy recovery like?

Colonoscopies are common, simple procedures, and you’ll be able to go back to your usual routine the next day. After the colonoscopy, you will be taken to an observatory area for 30 to 60 minutes until the side effects of the medication wear off. If your doctor removed a polyp during the colonoscopy, you might need to be on a temporary special diet. If no abnormalities were found, you should be able to eat once you get home. After you get home, you should spend the rest of the day relaxing.

Can I drive myself home or take a bus or taxi after my procedure?

Due to the sedation given during the procedure, you are considered legally impaired. The sedation medication impairs your judgment and reflexes. You will not be permitted to drive for 24 hours following your procedure. A trusted person must be with you to drive you home or accompany you on public transit. They should also stay with you until the next day.

After the procedure, when will I have a normal bowel movement?

Because your intestines were completely cleaned out for your procedure, it may take a couple of days of eating solid foods before you have a bowel movement.

Can I go back to work after my procedure?

Due to the sedation given during the procedure, you should plan to rest at home for the remainder of the day. You may resume your usual activities 24 hours after your procedure.

Are There Colonoscopy Side Effects? 

The most frequent side effects are slight abdominal pain and cramping caused by the air used to inflate the colon during the procedure. This discomfort usually passes quickly and only lasts a few hours. Immediately following the colonoscopy, you may experience side effects from the medications and sedatives, and those will wear off throughout the day. It’s common to feel sleepy, groggy or confused.

Colonoscopy Prep Infographic