About Your Flexible Sigmoidoscopy

Time to Read: About 7 minutes

This information will help you get ready for your flexible sigmoidoscopy (sig-MOY-DOS-koh-pee). A flexible sigmoidoscopy is an exam of your rectum and lower colon.

During your flexible sigmoidoscopy, your healthcare provider will use a flexible tube called an endoscope to see the inside of your rectum and lower colon on a video screen. They can also take a biopsy (small tissue sample) or remove a polyp (growth of tissue) during your procedure.

1 Week Before Your Procedure

Ask about your medications

You may need to stop taking some of your medications before your procedure. Talk with your healthcare provider about which medications are safe for you to stop taking. We’ve listed some common examples below.

Anticoagulants (blood thinners)

If you take a blood thinner (medication that affects the way your blood clots), ask the healthcare doing your procedure what to do. Whether they recommend you stop taking the medication depends on the type of procedure you’re having and the reason you’re taking a blood thinner.

Examples of common blood thinners are listed below. There are others, so be sure your care team knows all the medicine you take. Do not stop taking your blood thinner without talking with a member of your care team.

  • Apixaban (Eliquis®)
  • Aspirin
  • Celecoxib (Celebrex®)
  • Cilostazol (Pletal®)
  • Clopidogrel (Plavix®)
  • Dabigatran (Pradaxa®)
  • Dalteparin (Fragmin®)
  • Dipyridamole (Persantine®)
  • Edoxaban (Savaysa®)
  • Enoxaparin (Lovenox®)
  • Fondaparinux (Arixtra®)
  • Heparin (shot under your skin)
  • Meloxicam (Mobic®)
  • Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil®, Motrin®) and naproxen (Aleve®)
  • Pentoxifylline (Trental®)
  • Prasugrel (Effient®)
  • Rivaroxaban (Xarelto®)
  • Sulfasalazine (Azulfidine®, Sulfazine®)
  • Ticagrelor (Brilinta®)
  • Tinzaparin (Innohep®)
  • Warfarin (Jantoven®, Coumadin®)

Medications for diabetes

If you take insulin or other medications for diabetes, ask the healthcare provider who prescribes your medication what to do the morning of your procedure. You may need to change the dose before your procedure.

If you take metformin (such as Glucophage® or Glumetza®) or a medication that contains metformin (such as Janumet®), don’t take it the day before or the day of your procedure.

If you take any other oral medications (medications that you swallow) for your diabetes, don’t take them the day before or the day of your procedure.

Tell your healthcare provider if you have an AICD

Tell your MSK healthcare provider if you have an automatic implantable cardioverter-defibrillator (AICD). If you have an AICD, you’ll need to have your procedure done at Memorial Hospital, MSK’s main hospital.

Get a letter from your doctor, if needed

  • If you have an automatic implantable cardioverter-defibrillator (AICD), you’ll need to get a clearance letter from your cardiologist (heart doctor) before your procedure. A clearance letter is a letter that says you can safely have the procedure.
  • If you’ve had chest pain, dizziness, trouble breathing, or have fainted in the last 6 weeks, you need to be checked by your doctor, and get a clearance letter from your doctor before your procedure.

Your MSK doctor’s office must have your clearance letter at least 1 day before your procedure.

Arrange for someone to take you home

You must have a responsible care partner take you home after your procedure. A responsible care partner is someone who can help you get home safely. They should be able to contact your care team if they have any concerns. Make sure to plan this before the day of your procedure.

If you don’t have a responsible care partner to take you home, call one of the agencies below. They’ll send someone to go home with you. There’s a charge for this service, and you’ll need to provide transportation. It’s OK to use a taxi or car service, but you still need a responsible care partner with you.

Agencies in New York Agencies in New Jersey
VNS Health: 888-735-8913 Caring People: 877-227-4649
Caring People: 877-227-4649  


Buy supplies

  • 1 (10-ounce) bottle of Citrate of Magnesia (magnesium citrate)
  • 1 saline enema (such as Fleet® enema)
  • Clear liquids
  • Petroleum jelly (Vaseline®) or A & D® ointment

5 days before your procedure

Stop taking iron supplements

If you take an iron supplement, stop taking it 5 days before your procedure. Iron supplements can cause color changes in your stool. This can make it harder for your doctor to see your colon clearly.

3 Days Before Your Procedure

An endoscopy nurse will call you between and 3 days before your procedure. They’ll review the instructions in this guide with you and ask you questions about your medical history. The nurse will also review your medications and tell you which medications to take the morning of your procedure.

The Day Before Your Procedure

Starting the day before your procedure, do not eat anything. Follow a clear liquid diet.


Follow a clear liquid diet

A clear liquid diet includes only liquids you can see through. Examples are listed in the “Clear Liquid Diet” table. While you’re on this diet:

  • Don’t eat any solid foods.
  • Make sure to drink plenty of liquids other than water, coffee, and tea. This helps to make sure you get enough calories and if an important part of your preparation for your procedure. Try to drink at least 1 (8-ounce) glass of liquid every hour you’re awake.
  • Don’t drink anything red, purple, or orange.

If you have diabetes, only drink sugar-free clear liquids and check your blood sugar level often. If you have any questions, talk with your healthcare provider.

Clear Liquid Diet
  Drink Do Not Drink
  • Clear broth, bouillon, or consommé
  • Any products with particles of dried food or seasoning
  • Gelatin, such as Jell-O®
  • Flavored ices
  • Hard candies, such as Life Savers®
  • Anything red, purple, or orange
  • Clear fruit juices, such as apple, white cranberry, lemonade, or white grape
  • Soda, such as 7-Up®, Sprite®, ginger ale, or seltzer
  • Gatorade®
  • Black coffee
  • Tea
  • Water
  • Juices with pulp
  • Nectars
  • Milk or cream
  • Alcoholic beverages
  • Anything red, purple, or orange

Note the time of your procedure

A staff member will call you after (noon) the day before your procedure. The staff member will tell you what time you should arrive for your procedure. If you’re scheduled for your procedure on a Monday, they’ll call you the Friday before. If you don’t get a call, call your healthcare provider’s office.

If you need to cancel your procedure, call the healthcare provider who scheduled it for you.

Take your bowel preparation

Between and , drink the 10-ounce bottle of Citrate of Magnesia. It will make you have many bowel movements and diarrhea (loose or watery bowel movements). It usually works within 30 minutes, but may take as long as 3 hours.

After your bowel preparation, you can keep drinking clear liquids until 4 hours before your scheduled arrival time.

The Day of Your Procedure

  Starting 4 hours before your scheduled arrival time, do not eat or drink anything. This includes water, hard candy, and gum.


Give yourself an enema

Start the enema 4 hours before your scheduled arrival time. This may be early in the morning. Follow the steps below.

  1. Apply Vaseline or A & D ointment to the area around your anus. This prevents irritation.
  2. Lie on your left side with your right knee bent in toward your chest.
  3. Take the protective cap off the enema bottle. Insert the tip into your rectum.
  4. Squeeze the bottle until it’s empty.
  5. Remove the tip from your rectum. Keep lying on your left side. Hold the liquid in your rectum until you feel the urge to move your bowels. This usually takes about 5 to 10 minutes.
  6. Go to the bathroom to let the liquid out of your rectum into the toilet.

If you see any stool (poop) in the toilet, fill the enema bottle with room temperature tap water and repeat the steps above. Repeat the enema until you don’t see any stool. It’s okay if the liquid from the enema doesn’t change color.

Things to remember

  • Take only the medications your healthcare provider told you to take the morning of your procedure. Take them with a few sips of water.
  • Don’t put on any lotion, cream, powder, makeup, perfume, or cologne.
  • Remove any jewelry, including body piercings.
  • Leave valuable objects (such as credit cards and jewelry) at home.
  • If you wear contact lenses, wear your glasses instead.

What to bring

  • A list of the medications you take at home, including patches and creams.
  • Your rescue inhaler (such as albuterol for asthma), if you have one.
  • A case for your glasses.
  • Your Health Care Proxy form, if you have completed one.

Where to park

MSK’s parking garage is on East 66th Street between York and 1st avenues. If you have questions about prices, call 212-639-2338.

To get to the garage, turn onto East 66th Street from York Avenue. The garage is about a quarter of a block in from York Avenue. It’s on the right (north) side of the street. There’s a tunnel you can walk through that connects the garage to the hospital.

There are other parking garages on:

  • East 69th Street between 1st and 2nd avenues.
  • East 67th Street between York and 1st avenues.
  • East 65th Street between 1st and 2nd avenues.

Paid valet parking is available at the David H. Koch Center for Cancer Care.

Where to go

Your procedure will take place at one of these locations:

  • David H. Koch Center
    530 East 74th Street
    New York, NY 10021
    Take the elevator to the 8th floor.
  • Endoscopy Suite at Memorial Hospital (MSK’s main hospital)
    1275 York Avenue (between East 67th and East 68th Streets)
    New York, NY 10065
    Take the B elevator to the 2nd floor. Turn right and enter the Endoscopy/Surgical Day Hospital Suite through the glass doors.
  • MSK Monmouth
    480 Red Hill Road
    Middletown, NJ 07748

What to expect

Once you arrive

Once you arrive, you’ll be asked to state and spell your name and date of birth many times. This is for your safety. People with the same or similar names may be having procedures on the same day.

After changing into a hospital gown, you’ll meet your nurse. They’ll place an intravenous (IV) catheter into one of your veins, usually in your hand or arm. The IV will be used to give you anesthesia (medication to make you sleep) during your procedure. You may also get fluids through the IV before your procedure.

You’ll talk with your doctor before your procedure. They’ll explain the procedure and answer your questions.

During your procedure

When it’s time for your procedure, you’ll go into the procedure room and be helped onto an exam table. Your healthcare provider will set up equipment to monitor your heart, breathing, and blood pressure. You’ll get oxygen through a thin tube that rests below your nose.

You’ll get anesthesia through your IV, which will make you fall asleep. Once you’re asleep, your doctor will examine your rectum, then use a flexible scope to see the inside of your rectum and the end of your colon. Your doctor will take biopsies if needed.

After Your Procedure

Your nurse will continue to monitor your heart, breathing, and blood pressure. Once you’re fully awake, your nurse will remove your IV. Your nurse will explain your discharge instructions to you before you go home.

At home

  • Don’t drink alcoholic beverages for 24 hours (1 day) after your procedure.
  • You might have a little bleeding during your bowel movements. This may last for up to 24 hours after your procedure.

When to Call Your Healthcare Provider

Call you healthcare provider if you have any of the following:

  • A fever of 101 °F (38.3 °C) or higher
  • Chest pain or shortness of breath (difficulty breathing)
  • Severe pain, hardness, or swelling in your abdomen (belly)
  • Bleeding from your rectum that lasts more than 24 hours
  • Weakness, faintness, or both
  • Any other questions or concerns

Last Updated

Monday, July 17, 2023

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