Flexible sigmoidoscopy | Cancer Research UK
Cancer Research UK on Google+ Cancer Research UK on Facebook Cancer Research UK on Twitter
 

A quick guide to what’s on this page

Flexible sigmoidoscopy is a test that looks inside the lower part of your large bowel. It is also called bowel scope or flexisig. You usually have this test in the endoscopy unit of the hospital. The test itself only takes between 5 and 15 minutes, but you should expect to be at the hospital for up to 2 hours.

Before a flexible sigmoidoscopy

Your lower bowel needs to be empty to have this test. So you may be sent a small enema to have at home. Or you may have it when you get to the hospital. After the enema, you can’t eat or drink until after the sigmoidoscopy. Some hospitals may let you drink clear fluids (such as water and black tea or coffee) before the test.

Instead of an enema, you may need to drink a liquid bowel preparation (laxative) and follow a special diet for a couple of days before the test. The hospital will tell you what you have to do.

Having a flexible sigmoidoscopy

You lie on your left side with your knees bent. A nurse or doctor puts a flexible tube called a colonoscope into your back passage and up into the lower part of your large bowel. They put a small amount of gas into your bowel so that it is easier to see the bowel lining.

The nurse or doctor can take photographs of the bowel lining and samples of tissue (biopsies). They may remove any growths in the bowel (polyps) with a wire loop put down the colonoscope.

You can usually go home soon after having the test. You may feel bloated and have some mild cramping pain for up to a couple of hours afterwards.

Possible risks with sigmoidoscopy

Flexible sigmoidoscopy is a safe test for most people. But it has possible risks. These include bleeding from the back passage or a hole in the bowel wall (perforation). These are rare.

Your nurse will give you instructions on what to look out for and who to contact if you have any problems at home.

Results

If your doctor or nurse took any biopsies or polyps, you should receive the results in 2 weeks.

 

What is a flexible sigmoidoscopy?

A flexible sigmoidoscopy looks at the inner lining of the back passage (rectum) and left side of your large bowel (colon). It is also called bowel scope or flexisig.

A doctor or specialist nurse uses a thin flexible tube called a colonoscope. This has a small light and camera at one end. The doctor or nurse puts the tube into your back passage and gently moves it up into the lower part of your bowel. They can see the pictures of the inside of your bowel on a TV monitor.

You usually have this test in the endoscopy unit at the hospital. It may take between 5 to 15 minutes. But you should expect to be in the department for up to 2 hours.

 

Why you might have a flexible sigmoidoscopy

There are a number of reasons why you may need a flexible sigmoidoscopy. These include

  • To help find out the cause of your bowel symptoms
  • To check a condition you have been diagnosed with in the past
  • To look for early signs of cancer as part of the bowel cancer screening programme
 

Before a flexible sigmoidoscopy

Before your appointment you will receive a letter with details of how to prepare for your sigmoidoscopy.

Emptying the bowel with an enema

The lower part of your bowel needs to be empty when you have the test. So you may be sent a small enema to have at home, a couple of hours before your appointment. Or you may have the enema when you arrive at the endoscopy unit.

An enema is a small plastic pouch that contains liquid. The pouch has a nozzle. You lie on your left side, with a towel underneath you. You gently push the nozzle into your back passage and squeeze the pouch so that the liquid goes into your lower bowel. You need to try and hold onto the liquid for 5 to 10 minutes if possible, before going to the toilet.

It is important that you follow the instructions on the enema leaflet carefully. If you have any questions, call the number on your hospital appointment letter.

The effects of the enema should stop within an hour, so you shouldn’t have any problems travelling to the hospital for your appointment. The enema keeps your bowel clear for several hours.

You can normally eat and drink as usual up until you have the enema. Then you shouldn’t eat or drink until after your test. Some hospitals may let you drink clear fluids (such as water and black tea or coffee) during this time.

Emptying the bowel with a laxative

You may need to drink a liquid bowel preparation (laxative) instead of having an enema. You start taking this the same day, or the day before your test. You will have instructions of how and when to take the laxative. You need to follow these carefully.

You will also need to follow a special diet for a couple of days. You can’t have solid food from the day before your test. When you start taking the laxatives, it is important to drink plenty of clear fluids.

After taking laxatives you will need to go to the toilet often. The need to go may be very sudden. You may also have stomach cramps. So you need to stay at home for at least a few hours after taking the laxatives so that you are close to a toilet.

Medicines

If you are taking iron tablets, you will need to stop taking them about a week before your appointment. If you normally take drugs that can cause constipation, you may need to stop taking these up to 7 days before your test. Your appointment letter will give you more details about this.

Contact the hospital for advice as soon as possible before your appointment if you take medicines to thin your blood such as aspirin, clopidogrel or warfarin, or you are diabetic.

At the hospital

When you arrive at the endoscopy unit, a nurse will talk to you about what to expect. They will ask you about your medical history and any medicines you are taking. They will answer any questions you may have.

The nurse or a technician will ask you to change into a gown. They may also give you paper shorts to wear, which have an opening at the back. The nurse will give you an enema if you did not have one at home.

You can take a friend or relative with you to the hospital for support. They can normally wait in the reception area while you have the test.

 

Having a flexible sigmoidoscopy

You lie on a narrow bed, on your left side with your knees bent. You don’t normally need drugs to make you drowsy (sedation) for this test.

The doctor or specialist nurse gently puts the colonoscope into your back passage and up into the large bowel. This is not usually painful but it can be uncomfortable. If you find it too uncomfortable at any stage, tell the doctor or nurse and they will stop.

You may have pain relief using gas and air (Entonox). This is a quick acting form of pain relief that you breathe in through a mouth piece.

Diagram showing a sigmoidoscopy

The doctor or nurse puts a small amount of gas through the colonoscope into your bowel. The gas expands the bowel so that they can see the lining of the bowel clearly. This can make you feel bloated.

The doctor or nurse can take photographs of the bowel lining. If they see any abnormal areas they will take tissue samples (biopsies). If you have any growths in the bowel lining (polyps), they can remove them with a wire loop that they put down the colonoscope.They send the samples to the laboratory to be looked at closely by a pathologist.

 

After the test

You should be able to go home as soon as the test is over. You can usually eat and drink as normal.

You may feel bloated and have mild cramping pain after the test. This is due to the gas the doctor or nurse put into your bowel. This discomfort should pass within a couple of hours. Walking around, or having warm drinks or peppermint water may help you to pass wind.

 

Possible risks with flexible sigmoidoscopy

A sigmoidoscopy is a safe test for most people. But like all medical tests it does have possible risks. Doctors make sure the benefits of having the test outweigh these risks.

After having a biopsy or polyp removed, you may have some bleeding. This is usually a small amount and stops on its own within a couple of days. Rarely, you may need a blood transfusion or surgery to stop the bleeding.

There is a very small risk of making a hole in the bowel wall, called a perforation. Although this is rare, it is serious. You will be admitted to hospital and may have to go to the operating theatre for emergency surgery to repair your bowel wall. And you will need strong antibiotics to prevent infection.

Your nurse will give you clear instructions on what to look out for and who to contact if you have any problems at home.

 

The results

If the nurse or doctor had to take any biopsies or remove polyps you will need to wait up to 2 weeks to get the results. These will be sent to your specialist, who will give them to you. If your GP sent you for the test, the results will be sent directly to the GP surgery.

Understandably, waiting for results can make you anxious. Try to remember to ask your doctor how long you should expect to wait for the results.

If you haven’t heard anything a couple of weeks after your test, phone your doctor’s secretary or GP surgery to check if the results are back.

Rate this page:
Submit rating

 

Rated 4 out of 5 based on 11 votes
Rate this page
Rate this page for no comments box
Please enter feedback to continue submitting
Send feedback
Question about cancer? Contact our information nurse team

No Error

Updated: 19 February 2016