Diagnosing ulcerative colitis

To diagnose ulcerative colitis, your GP will first askabout your symptoms, general health and medical history.

They'll also physically examine you, checking for signs such as paleness (caused by Iron deficiency anaemia ) and tenderness inyour tummy(caused by inflammation).

A stool sample can be checked for signs of infection, as gastroenteritis (infection of the stomach and bowel) can sometimes have similar symptoms to ulcerative colitis.

Blood tests may also be carried out to check for anaemia and to see if there's inflammation on any part of your body.

Further tests

If your GP suspects you may have inflammatory bowel disease (a term mainly used to describe two diseases: ulcerative colitis or Crohn's disease ), you may be referred to hospital for further tests.

These could include an X-ray or computerised tomography (CT) scan to rule out serious complicationsand a detailed examination of your rectum and colon.

The two types of examination you may have are described below.


A diagnosis of ulcerative colitis can be confirmed by examining the level and extent of bowel inflammation. This is initially done by using a sigmoidoscope, a thin, flexible tube containing a camera that's inserted into your rectum (bottom).

A sigmoidoscopy can also be used to remove a small sample of tissue from your bowel, soit can be tested in a laboratory. This is known as a biopsy .

The procedure can be uncomfortable, and you can be given a sedative to help you relax. It usually takes around 15 minutes and you can often go home the same day.

During this procedure, only the rectum and lower part of the colon are examined. If it's thought your ulcerative colitis has affected more of your colon, another examination will be required. This is known as a colonoscopy.


A colonoscopy uses a flexible tube containing a camera calleda colonoscope, which allows your entire colon to be examined.A biopsy sample can also be taken.

Before having a colonoscopy, your colon needs to be completely empty so you'll need to take strong laxatives beforehand.

Acolonoscopy can be uncomfortable, butyou'll be given sedatives and pain medications to help you relax and make the procedure as painless as possible. The procedure takes around half an hour and you'll be able to go home the same day.

The anus is the opening at the end of the digestive system where solid waste leaves the body.
A biopsy is a test that involves taking a small sample of tissue from the body so it can be examined.
Blood tests
During a blood test, a sample of blood is taken from a vein using a needle, so it can be examined in a laboratory.
An enema is an injection of fluid into the large intestine/colon to empty the bowel. It can also be used to make the bowels show up more clearly in an X-ray.
Inflammation is the body's response to infection, irritation or injury, which causes redness, swelling, pain and sometimes a feeling of heat in the affected area.
Stool (also known as faeces) is the solid waste matter that is passed from the body as a bowel movement.
An ulcer is a sore break in the skin, or on the inside lining of the body.
An X-ray is a painless way of producing pictures of the inside of the body using radiation.
Content supplied by the NHS Website

Medically Reviewed by a doctor on 30 Nov 2016