How do I get treatment

For London Colorectal please telephone:

  • +44 (0) 20 7403 6061

For Gastroenterology please call:

  • +44 (0) 20 7234 2292


Having a Flexible Sigmoidoscopy

You have been advised to have a flexible sigmoidoscopy. As with many medical tests, your main anxieties before a flexible sigmoidoscopy will be due to a fear of the unknown. The purpose of this information is to explain to you what to expect so that you need not have any worries about your procedure.

The following information may not answer all your queries, but if you have any worries or concerns, please do not hesitate to contact your consultant’s office to go over these.

What is a flexible sigmoidoscopy?

Bowel problems are extremely common and can be difficult to diagnose without looking inside the lower gut. Generally the best way of doing a quick examination of the lower bowel, the area where most problems tend to occur, is by carrying out something called a flexible sigmoidoscopy (flexi-sig). Your doctor may have explained to you that your symptoms might need investigating in this way. The great advantage of this special examination is that it can be done quickly (just 3-4 minutes), gently, without too much discomfort, and it can provide rapid assurance about your symptoms with just one visit. It can also save the need for further tests.

What is a flexible sigmoidoscope?

The flexible sigmoidoscope is a narrow, relatively soft steerable tube, which can be passed, after lubrication with some jelly, into the back passage. As it is flexible, it can go round the bends in your bowel. There are bundles of fine glass fibres in the flexible sigmoidoscope, which allow light to illuminate the inside of the bowel so it can be seen more clearly whilst still allowing flexibility. In the majority of cases flexi-sig is much more comfortable and gives a much clearer result than the old system of examination with a short rigid steel tube.

Preparation and cleaning of the bowel:

This is done on admission, with either a suppository or an enema.

The examination:

The person undertaking your examination (the endoscopists) will have had special training in this procedure. You will probably be asked to lie on your left side, with your knees slightly bent. A nurse will stay with you throughout the test. The nurse may also help the endoscopists complete the examination by gently pushing on your tummy. Air will be slowly introduced into the bowel to slightly enlarge it so that the tube can pass along it more easily and enable the endoscopists to get the best possible pictures of the bowel lining. This air sometimes causes a little discomfort, similar to wind, but this will not last long and disappears soon after the examination has finished. On average the procedure takes about 3-4 minutes, but can be stopped at any stage if it gets too uncomfortable. It may occasionally take a little longer. The tube can be passed up to 60cm (24 inches) into the bowel. The endoscopists and nurse will talk to you throughout so that you can let them know if it becomes uncomfortable. You will have complete control on stopping the procedure at any point, but any discomfort you experience will disappear very quickly. A flexi-six often avoids the need for an x-ray, which would involve coming back on another day and having the bowel cleared out with a laxative over the previous 24 hours. Because the flexi-sig examination is usually only mildly uncomfortable, you do not need to be sedated or have pain-killers.

What if a biopsy is taken?

If there is a need to look more closely at the lining of the bowel, the endoscopists may take a biopsy.


This is when a small piece of tissue is taken from inside the bowel and sent to the laboratory for examination under a microscope. This will not hurt, but it helps to identify the exact cause of the problem.

Going home after the examination:

After the examination you will be able to go home quite quickly. You may have to sit on the toilet and pass some wind before you leave and you may have a little discomfort with wind for some 24 hours afterwards.


A flexi-sig is a simple, safe and very effective procedure, which is designed to reassure you. It can be done without sedation or injections to make you sleepy, and the preparation of the bowel is simply and very quick. The procedure is often done with little discomfort, which is why it can be performed in the outpatient department.

Some Conditions which your consultant may be looking for/find in your bowel:


This is a small projection from the surface of the bowel. It can be on a stalk, although sometimes it can be relatively flat. The doctor may take a biopsy of this.

Diverticular Disease:

This is when little pockets form on the bowel and is a very common condition as one gets older. Normally this requires no specific treatment.


This is when the lining of the bowel becomes inflamed and often causes bleeding and loose motions.

If the examination is normal:

Piles (haemorrhoids):

These are blood vessels that project into the rectum just above the anus. They can cause bleeding, soreness and sometimes prolapse – this is where the piles come out through the anus and may be seen or felt.


This is a split or tear in the skin just on the outside of the anal opening.


This is a narrow tract or joining between the anal canal and the surface of the skin close to the anus. It can also cause a boil or abscess.

Pruritus Ani:

This is a term used to describe very severe itching around the bottom of the anus.

Bowel Spasm:

This is a cramp like contraction in the bowel that can cause some pain.

Irritable Bowel Syndrom:

This is a term used to describe all sorts of symptoms, including bowel spasm, which are not due to serious causes. It may take the form of pain in the tummy, constipation, diarrhoea and bloating.

In a few cases it may be necessary to undergo a further examination, such as :

Colonoscopy –

please see information for this in our patient information.

Barium Enema:

This is an x-ray of the bowel and performed after taking strong laxatives at home. It is done without sedation in the x-ray department.