Having a flexible sigmoidoscopy

Flexible sigmoidoscopy

The procedure takes about 15 minutes.

An endoscopy nurse will be with you during the whole procedure to reassure you.

It is usually performed with gas and air (Entonox). Entonox is a common type of pain relief that is used for many different procedures and conditions, like relieving pain during childbirth.

You can also have sedation or an injection of painkillers.

Sedation is a medicine that makes you relaxed and sometimes sleepy, but does not put you to sleep. Your endoscopist will explain this to you in more detail.

If you are having sedation, you must have an adult who can take you home and stay with you overnight. If you do not, your procedure might be cancelled.

During the procedure

  1. You will be asked to lie down on your left-hand side on a couch with your knees bent.
  2. The endoscopist will start by putting a finger into your bottom to perform a rectal exam.
  3. This will help lubricate the anal passage, and to check if there are any haemorrhoids or growths in your anal passage.
  4. The endoscope will then be put into your lower bowel through your bottom.
  5. Air will be passed down a channel in the endoscope. This will expand your bowel to make it easier to see during the procedure. 
  6. This might make you feel slightly bloated. You might feel the need to go to the toilet, but you will not be able to as your bowel will be empty.

Many people fart during the test. This is perfectly normal and is nothing to be embarrassed about.

If you have polyps, your endoscopist can remove these. You will not feel this. When a polyp is particularly big or in a difficult position, you might need to come back another time for it to be removed. We will re-book your appointment on a special list.

Pain

  • You might have some cramps and tummy pain during or after the procedure. This is from the air that we use to inflate your bowel during the procedure. 
  • You might also have short periods of discomfort or pain from certain parts of the procedure. This should not last long.
  • Sometimes, the nurse will press gently on your stomach or your position might be changed to help the passage of the endoscope.
  • You will not feel anything if any biopsies are taken.

After a sigmoidoscopy

The nurse will take you to the recovery area. If you had sedation, the nurse will check you regularly and monitor you for any complications. You will be in the recovery area for 30 minutes, or until you are fully awake. After that, we will take you to the discharge area.

If you had Entonox, you do not need to wait in the recovery area. We will take you straight to the discharge area.

You might still feel a little bloated from the air passed into your bowel during the procedure. This should pass quite quickly.

While waiting in the discharge area we will offer you some tea and biscuits. The discharge nurse will give you a copy of your report and explain it to you. You can leave the hospital straight after you’ve been discharged.

After you leave hospital

You can eat and drink normally, and should be able to carry out your usual activities if you did not have sedation

If you had sedation, you should rest for 24 hours after the test before you resume your normal activities. 

Call 999 or visit your nearest emergency department (A&E) if:

  • you get severe tummy (abdominal) pain
  • you have a high temperature (fever)
  • you are being sick (vomiting)
  • you are passing large amounts of blood after the test

Please take your endoscopy report with you.

Results

The discharge nurse will often be able to tell you your results before you leave the hospital. If you have had a sedative, it is a good idea to have someone with you when the results are being discussed, as you might not remember all of the details due to the sedative.

The results of any biopsies or polyps taken during the procedure will usually be available within 6 weeks

You and your GP will get a letter with the results and recommendations for your care and treatment.

You might be given an appointment to come back to the clinic. This will be posted out to you.

Follow-up appointment

If your results suggest that you need a follow-up appointment, the Patient Access Team will contact you to arrange this. 

You and your GP will then get a letter from the clinic telling you if you need to return to the hospital, or if you can be discharged back to your GP.

Useful information

GUTS UK is a UK charity that offers information, support and research into diseases of the digestive tract that includes the gut, liver and pancreas.

Resource number: 0920/VER9
Last reviewed: December 2025
Next review due: December2028

 

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