Ulcerative colitis - Tests and diagnosis

Ulcerative colitis can be a difficult condition to diagnose and is often confused with other conditions. It is not usual to test for ulcerative colitis unless you are experiencing specific symptoms or you are at a high risk - for example, if you have a close relative with inflammatory bowel diseaseA group of inflammatory conditions of the intestine. The two major forms are Crohn’s disease and ulcerative colitis..

It can also be very difficult to say exactly which condition you have, based only on your symptoms. It is important to get a correct diagnosisThe process of determining which condition a patient may have. so that you get the right treatment.

There is no single test for ulcerative colitis. However, there are some tests that will narrow down the possible causes of any worrying symptoms and help your doctor to make a diagnosisThe process of determining which condition a patient may have.. These tests will find out if there is inflammationThe body’s response to injury. in your gastrointestinal tractThe gut, which begins at the mouth and ends at the anus. and they will also check the condition of your liverA large abdominal organ that has many important roles including the production of bile and clotting factors, detoxification, and the metabolism of proteins, carbohydrates and fats..

It is important when you are first tested for ulcerative colitis that other suspected conditions are excluded. These include Crohn's disease, bowel infections and irritable bowel syndrome (IBS). There are some simple initial tests that your doctor may recommend to rule out any other illnesses before you are referred on for diagnostic testing.

Initial tests

The most common initial tests include:

  • Blood tests to check for problems such as anaemiaA reduced level of haemoglobin, which carries oxygen in the blood. Anaemia causes tiredness, breathlessness and abnormally pale skin., inflammationThe body’s response to injury., infectionInvasion by organisms that may be harmful, for example bacteria or parasites., bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. chemical and mineral deficiencies that may have been caused by diarrhoeaWhen bowel evacuation happens more often than usual, or where the faeces are abnormally liquid., as well as assessment of liverA large abdominal organ that has many important roles including the production of bile and clotting factors, detoxification, and the metabolism of proteins, carbohydrates and fats. function, and tests to look for particular antibodiesSpecial proteins in the blood that are produced in response to a specific antigen and play a key role in immunity and allergy. that may indicate which type of IBDAn abbreviation for inflammatory bowel disease, a group of inflammatory conditions of the intestine. The two major forms are Crohn’s disease and ulcerative colitis. is present
  • Stool tests may reveal bacterial infectionInvasion by organisms that may be harmful, for example bacteria or parasites. or inflammationThe body’s response to injury. in your gastrointestinal tractThe gut, which begins at the mouth and ends at the anus.. Your doctor or nurse will give you a container so that you can provide a sample in private.

Further tests

After performing a thorough examination and common initial tests, a more detailed series of diagnostic tests may be recommended to help your doctor make the diagnosisThe process of determining which condition a patient may have. of ulcerative colitis, or to exclude other conditions. These may be carried out in a hospital and may include:

  • Endoscopy - either sigmoidoscopy and colonoscopyExamination of the colon and rectum with a colonoscope, an imaging instrument that is inserted through the anus., depending on which part of the gastrointestinal tractThe gut, which begins at the mouth and ends at the anus. is being examined. A biopsyThe removal of a small sample of cells or tissue so that it may be examined under a microscope. The term may also refer to the tissue sample itself. may be taken at the same time if necessary.
  • X-rays to look at parts of the gastrointestinal tractThe gut, which begins at the mouth and ends at the anus. that endoscopyExamination of the inside of the body using a tube equipped with a light source and either a small camera or an optical system. is not able to reach
  • White bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. cellThe basic unit of all living organisms. scan (scintigraphy) to determine the location and severity of inflammationThe body’s response to injury. in the gastrointestinal tractThe gut, which begins at the mouth and ends at the anus., as well as to identify complications such as abscesses
  • Ultrasound scan
  • Computerised tomography (CTA scan that generates a series of cross-sectional X-ray images.) scanning
  • Magnetic resonance imaging (MRIAn abbreviation for magnetic resonance imaging, a technique for imaging the body that uses electromagnetic waves and a strong magnetic field.).

Getting the results

There may be a wait for the results of your diagnostic tests. This is because the information needs to be looked at by specialists, who may send the results to your doctor. It is important to ask how long it will take to get the results of any tests that are done, and whether you need to telephone or make an appointment to get the results.