Diverticular disease
Diverticular disease can be difficult to diagnose from the symptoms alone because there are many other conditions that cause similar symptoms, such as irritable bowel syndrome (IBS), a common but poorly understood condition that causes inflammation of the bowel.
Therefore, as a first step, your GP may recommend that you have some blood tests. These tests cannot diagnosis diverticular disease but they can help to rule out other conditions.
Colonoscopy
To confirm the presence of diverticula (small pouches in the side of the colon) the inside of your large intestine (colon) will be looked at. One way of doing this is through a technique known as a colonoscopy.
During a colonoscopy, a thin tube with a camera at the end (a colonoscope) is placed through your rectum and guided into your colon. Before the procedure begins, you will be given a laxative to clear out your bowels.
Colonoscopies are not painful because they are done under local anaesthetic (medication that numbs the surrounding area). However, you may feel a little discomfort during the procedure.
Barium enema X-ray
Another technique for confirming the presence of diverticula is a barium enema X-ray. Barium is a liquid that shows up on X-rays. It is used to coat the inside surface of organs that do not show up on X-ray, such as the colon.
As with a colonoscopy, you will be given a laxative to clear out your bowels before you have a barium enema X-ray.
During the procedure, a tube is inserted into your rectum. The barium liquid is squirted into the tube and passed up into your rectum. A series of X-rays are then taken. Although the procedure is not painful, some people may find it embarrassing.
For a few days after having a barium enema X-ray, your stools will appear white and discoloured due to the barium passing out of your body. It is nothing to worry about.
Diverticulitis
If you have had a previous history of diverticular disease, your GP will usually be able to make a diagnosis of diverticulitis by carrying out a physical examination and asking you about your symptoms and medical history. A blood test may be taken because a high number of white blood cells can indicate the presence of infection.
Further tests will be needed if you have no previous history of diverticular disease. This is necessary to confirm the diagnosis and to rule out any other possible conditions, such as gallstones or a hernia.
A barium enema X-ray may be used, as well as a computerised tomography (CT) scan. A CT scan takes a series of X-ray scans, which are then reassembled by a computer to build up a more detailed 3-D image of the inside of your body.
A CT scan may also be used if your symptoms are particularly severe. This is to check whether the infection has spread to other parts of your body, or whether a complication, such as an abscess (a pus-filled cavity in the tissue), has occurred.
