Complications of diverticulitis affect 1 in 5 people with the condition. Those most at risk of developing complications are younger people (under 50 years of age) who need multiple admissions to hospital due to the severity of their symptoms.
Some of the complications that are associated with diverticulitis are discussed below.
Abscess
The most common complication of diverticulitis is the development of an abscess inside the large intestine (colon). An abscess is a pus-filled cavity or lump in the tissue. Abscesses are usually treated with a technique known as percutaneous abscess drainage (PAD).
A radiologist (a specialist in the use of imaging equipment, such as computerised tomography scans) will use an ultrasound or CT scanner to locate the site of the abscess.
A fine needle that is connected to a small tube will be passed through the skin of your abdomen (stomach) and into the abscess. The tube is then used to drain out the pus from the abscess. A PAD is performed under a local anaesthetic, so it is not particularly painful.
Depending on the size of the abscess, the procedure may need to be repeated several times before all of the pus has been drained away. If the abscess is very small - usually less than 4cm (1.5in) - it may be possible to treat it using antibiotics.
See the Health A-Z topic about Abscess for more information.
Fistula
After an abscess, a fistula is the second most common complication of diverticulitis. Fistulas are abnormal tunnels that connect two parts of the body together, such as your intestine and your abdominal wall or bladder.
If infected tissues come into contact with each other they can stick together. After the tissues have healed, a fistula may form. Fistulas can be potentially serious as they can allow bacteria in your large intestine (colon) to travel to other parts of your body, triggering infections, such as an infection of the bladder (cystitis).
Fistulas are usually treated with surgery to remove a small section of the colon that contains the fistula.
See the Health A-Z topic about Anal fistula for more information.
Peritonitis
In rare cases, an infected diverticula (pouch in your colon) can rupture (split), spreading the infection into the lining of your abdomen (stomach). An infection of the lining of the abdomen is known as peritonitis.
Peritonitis can be life-threatening, and requires immediate treatment with antibiotics. Surgery may also be required to repair any damage and to drain any pus that has built up.
See the Health A-Z topic about Peritonitis for more information.
Intestinal obstruction
If the infection has badly scarred your colon, your colon may become partially or totally blocked. A totally blocked colon is a medical emergency because without immediate medical help, the tissue of your colon will start to decay and eventually rupture (split), leading to peritonitis.
A partially blocked colon is not as urgent a situation as a fully blocked one, but treatment is still needed. If left untreated, it will affect your ability to digest food. It will also cause you considerable pain.
In some cases, the blocked part of your colon can be removed during a colon resection (surgically removing the affected part of the colon). However, if the scarring and blockage is more extensive, a temporary or permanent colostomy may be needed.
