Surgery for diverticulitis and diverticular disease

Photo of a patient at a doctor's appointment (PantherMedia / Monkeybusiness Images)

Bowel surgery can relieve long-term problems caused by diverticula – but there are risks involved. Surgery is sometimes necessary, though, in order to avoid serious complications of diverticulitis.

In non-emergency situations, it’s important to carefully consider the pros and cons of bowel surgery for diverticula-related problems before making a decision. This treatment is associated with risks, and there’s no guarantee that it will make the symptoms go away. Whether or not surgery is considered will depend on various factors, including the severity of the symptoms, how long you have had them, the risk of complications, and how effective other measures (such as dietary changes) have been.

Acute diverticulitis

Surgery usually isn’t necessary in people who have acute diverticulitis. But there are exceptions: If abscesses (collections of pus) have formed, and treatment with antibiotics isn’t successful, surgery is unavoidable. The aim is then to prevent serious complications such as the wall of the intestine tearing (perforation) or the inner lining of the tummy becoming inflamed (peritonitis), which can lead to blood poisoning (septicemia).

Even if other treatments are successful, surgery might still be a good idea if someone has a large abscess: About half of all people in this situation develop diverticulitis again within a few years – sometimes with serious complications. For this reason, surgery can have more of a benefit here. It is carried out once the inflammation has gone away. The risk of serious complications is also higher in people who have a weakened immune system or chronic kidney disease.

Chronic diverticular disease

People who have recurrent diverticulitis or chronic symptoms generally don’t develop serious complications. Although such complications are possible, they tend to be rare if the inflammation is “uncomplicated” – in other words, as long as no abscesses have formed. Sometimes recurrent inflammation can lead to the formation of fistulas (tunnel-like passageways between two organs) or narrowing of the intestine (stenosis). Fistulas increase the risk of complications, so surgery is generally recommended if they arise. Surgery may be recommended for stenosis too, depending on how narrow the intestine has become.

In every other situation, the main aim of treatment is to relieve symptoms in everyday life, such as abdominal pain and digestion problems. There is little research on how effective surgery is here compared with other treatments. Studies have suggested that – in some people – surgery can relieve the symptoms better than medication or a change in diet can. But sometimes the symptoms don’t go away despite surgery, or they come back again after a while. It is estimated that between 5 and 25 out of 100 people who have had surgery still have the symptoms afterwards.

For a long time it was thought that the risk of complications increases every time another episode of diverticulitis occurs. Because of this, some doctors also recommend surgery in people who have had recurrent uncomplicated diverticulitis. But studies have now shown the opposite to be true: The risk of complications is the highest the first time someone has diverticulitis – after that, it goes down a lot.

What happens during the surgery?

The most common type of surgery for all forms of diverticular disease is called sigmoid resection (sigmoidectomy). The sigmoid colon is the section of the large intestine that comes just before the rectum, at the end of the bowel. This is the section where the strain of emptying your bowels puts the most pressure on the wall of the intestine, so the most diverticula occur here. The surgery involves removing the sigmoid colon as well as a small area of the rectum. Because diverticula can also occur in other parts of the intestine, it’s usually not possible to remove all of them. After the affected section of intestine has been removed, the ends are sewn back together again.

In most cases, this is a minimally invasive procedure that is done by inserting instruments through small cuts in the abdominal wall (laparoscopy). But it can also be done by making a bigger cut (open surgery).

The bowel has to be completely empty beforehand. To empty it, you have to drink about 1 liter of a laxative solution and 2 to 3 liters of water the day before surgery. People can have an enema too, which is where fluid is put into the rectum in order to cleanse the bowel. It’s important that the bowel is empty so that none of its contents get into the abdominal cavity during surgery.

Illustration: Sigmoid resection: the most common type of surgery for diverticular disease - as described in the articleSigmoid resection: the most common type of surgery for diverticular disease

What are the risks of surgery?

There’s a risk of injury to the bowel or nearby organs during surgery. It may also lead to scarring in the abdominal cavity, which can cause pain or digestion problems.

Another possible risk is known as an anastomotic leak. This is where stitches that were used to sew the two ends of the intestine together come undone again soon after surgery. Bowel contents may leak into the abdominal cavity as a result, leading to dangerous inflammations there. Anastomotic leaks occur in about 3 out of 100 people who have had this surgery.

Out of every 100 operations, about

  • 2 abscesses,
  • 4 wound infections and
  • 3 episodes of major bleeding

occur too.

And there are the general risks associated with surgery, such as problems due to the anesthetic, pneumonia or thrombosis.

Surgery during peritonitis?

Complicated diverticulitis might lead to peritonitis (inflammation of the inner lining of the tummy). Pus might then spread inside the abdominal cavity and even cause blood poisoning. This is a medical emergency requiring urgent surgery. But this surgery usually doesn’t involve removing any sections of the bowel at first. Instead, the abdominal cavity is rinsed out and an artificial opening (colostomy) is made. This is because the inflammation has to clear up completely before doing a sigmoid resection. After a few months, the artificial opening can be closed again, and a sigmoid resection can be carried out.

Making a decision

Up until a few years ago, people who had chronic diverticular disease were nearly always advised to have surgery. Nowadays clinical guidelines encourage doctors to only do so if absolutely necessary. It’s a good idea to try out other options such as medication and dietary changes first. The decision regarding whether or not to have surgery will mainly depend on the symptoms in everyday life. Only certain groups of people need to consider the risk of diverticulitis-related complications when making this decision. Other medical conditions, the person’s age and life circumstances play an important role too.

Sometimes different doctors give different advice. Finding out as much as you can about the pros and cons of the treatment options, and getting a second opinion if you are unsure, can help you to make a decision.