About pouches in the large bowel

Pouches (diverticula) in the lining of the large bowel are formed in the muscle layer of the bowel wall. Some people have only a few pouches, but others may have more than a hundred. The number of pouches increases with age and is seen in more than half of all people aged 70 and older. Most people do not experience any discomfort.

Causes of pouches in the large bowel

The exact cause of pouches is unknown, but they are likely related to the fact that many people tend to develop constipation as they get older. Constipation may be caused by a low-fibre diet, irritable bowel syndrome or not drinking enough fluids. Over time, weak spots can form in the muscle layer of the bowel wall. These weak spots may not be able to withstand the pressure from stool inside the bowel, and this can lead to pouches.

Symptoms

Symptoms of pouches in the large bowel are usually vague. However, some people experience constipation, wind, stools that alternate between diarrhoea and being hard, and pain in the lower left side of the abdomen. The pain is often relieved after a bowel movement. 
 
In rare cases, symptoms such as inflammation in the pouches (diverticulitis) or bleeding may occur. 
Bleeding from the rectum or blood in your stool may look alarming, but it usually stops on its own. If you have bleeding from the bowel, you should contact a doctor. 
If the pouches become inflamed, symptoms include fever and constant pain in the lower left side of the abdomen. The pain often develops over several hours or days and may feel cramp-like. It is often accompanied by nausea and vomiting. Some people may also have wind, a swollen stomach, constipation or diarrhoea, and possibly bloody stools.

How the diagnosis is made

If the pouches are inflamed, we make the diagnosis by doing a CT scan and taking blood samples. If you have had inflammation in the pouches, we always follow up with an examination of your bowel using a flexible tube with a camera 4–6 weeks later, when the inflammation has settled. The purpose of this examination is to rule out other disease.

Treatment options

If you do not have any problems or discomfort, treatment is not necessary. If you tend to be constipated, we recommend treatment with a fibre supplement such as HUSK (psyllium), along with plenty of fluids. Try to drink 1½–2 litres of fluid a day.

If the pouches become inflamed, it may be necessary to take antibiotic tablets for 7–10 days. This may be the case if you have a high fever. In some cases, the antibiotics are given through a cannula in your hand, and you may need to stay in hospital for a few days.

What to watch out for

If you have been admitted to hospital for observation or treatment of inflammation in the pouches, you should watch out for the following symptoms when you return home:

• High fever.
• Bleeding.
• Increasing pain.
• Constipation or diarrhoea.

If you experience one or more of these symptoms, please contact your own doctor or call the emergency helpline 1813 outside your doctor’s opening hours.