Diverticular disease and diverticulitis

Most diverticula don’t cause any symptoms. Diverticular disease is typically associated with pain in the lower left part of the abdomen (belly) or – less commonly – the lower right part. It can also lead to bloating, constipation or diarrhea. The symptoms often come and go, but they may also be ongoing. They commonly get worse after meals, and then better again after going to the toilet and having a bowel movement (pooping). Sometimes diverticula bleed.

If diverticula become inflamed or infected (diverticulitis), they cause sudden dull pain in the lower belly, accompanied by a mild fever. Other symptoms include constipation, diarrhea, bloating, nausea and sometimes cramping too. Only in rare cases does diverticulitis lead to vomiting. If a doctor pushes down on your belly, your belly muscles automatically tense up (a reflex known as muscular defense). When they suddenly let go, the pain gets worse.

Diverticula develop in areas of the bowel wall where the muscles are weaker. They usually arise in the sigmoid colon. This s-shaped section of the large intestine (colon) is roughly 40 to 45 centimeters long and found just before the rectum. The contents of the bowel put the most pressure on the muscular wall here.

Some people are more likely to develop diverticula because of their genes. Further risk factors include weak connective tissue and problems with the wave-like movements of the bowel wall. Older and very overweight people are at greater risk, too.

The influence of lifestyle factors hasn’t yet been properly determined. A diet that is low in fiber can lead to constipation and hard stools, so it seems logical that too little fiber will increase the risk of diverticular disease. Eating a lot of red meat, smoking and not getting enough movement are also believed to be risk factors.

It is still not clear how diverticula become inflamed or infected and what increases the risk of this happening. But it is believed to be more likely in areas of reduced blood supply and if hard lumps of stool form in the diverticula.

Complications are more common in people who have a weakened immune system (for instance, after an organ transplant) or severe kidney disease. The long-term use of particular medications probably increases the risk of more serious complications. These medications include non-steroidal anti-inflammatory drugs (NSAIDs), steroids and opioids.

Many people have diverticula without knowing it. These sac-like pouches are more common in older age: About 13% of people under the age of 50 have diverticula, and about 50% of people over the age of 70 have them. They are similarly common in men and women.

About 1% of all people who have diverticula develop diverticulitis within ten years. It can occur at any age.

Diverticula often remain unnoticed if they don’t cause any symptoms. But they sometimes lead to chronic digestive problems and pain, or may become inflamed or infected.

Diverticulitis can usually be treated effectively and then goes away after a few weeks. But about 20% of those who have diverticulitis get it again at least once within a few years.

If the inflammation or infection spreads from the diverticula to the bowel wall, the surrounding area or nearby organs, complications can occur: Abscesses (collections of pus) or fistulas may develop. A fistula is an abnormal tunnel-like passageway between two organs, such as the bowel and the bladder. These complications must be treated quickly, often with surgery.

One rare but serious complication may arise if the wall of the bowel tears (intestinal perforation). If the contents of the bowel then leak out into the abdominal cavity, the inner lining of the belly (peritoneum) may become inflamed, leading to a life-threatening condition known as peritonitis. This typically causes severe belly pain, a hard belly, fever, nausea, a rapid heartbeat and general weakness. If symptoms like this occur, it's important to see a doctor right away.

In some people, diverticula keep becoming inflamed or infected despite having been treated successfully in the past. This can lead to scarring that causes the bowel to become narrow (intestinal stenosis), making it difficult for stool to pass through it. In the worst case, the bowel may become blocked (ileus).

The risk of complications is greatest when someone has diverticulitis for the first time. After that, further episodes are a lot less likely to lead to complications. The main consequences of recurring diverticulitis are chronic symptoms such as irregular bowel movements, bloating and abdominal (belly) pain.

Some people have ongoing symptoms although their bowel isn’t inflamed.

Diverticula that do not cause any symptoms are often only found by chance – for example, during a colonoscopy. If you go to the doctor because of symptoms you are experiencing, she or he will first ask about any other illnesses you have and medication you are taking. This is followed by a physical examination where they listen to your belly, and also feel your belly and inside your bottom. Depending on the symptoms, you may have blood and urine tests, and your temperature might be measured. You will usually have an ultrasound scan as well. If there is still no clear diagnosis, you may need to have a CT ( computed tomography) scan and perhaps a colonoscopy too (inspection of the inside of the bowel using a camera).

This can help to rule out other illnesses – the symptoms of diverticular disease are similar to the symptoms of conditions like appendicitis or irritable bowel syndrome (IBS).

Colonoscopies are too risky during acute diverticulitis because any infection could spread if the bowel is injured. But people are often advised to have a colonoscopy about 4 to 6 weeks after the symptoms have cleared up. This is to make sure that they weren’t caused by polyps, bowel cancer or another illness.

Eating enough fiber helps to make sure that your stool doesn’t get too hard. This could prevent discomfort or inflammation in people with diverticula. There’s a lot of fiber in whole-grain foods, vegetables, legumes (e.g. beans or lentils) and fruits. Physical exercise stimulates digestion too, but it's not clear whether it can prevent diverticula-related symptoms.

Sometimes people with diverticula are advised to avoid certain foods – particularly nuts, seeds, sweetcorn and popcorn. For a long time, it was thought that small bits of these foods could get stuck in diverticula and cause them to become inflamed or infected. But studies have shown that not to be true. So there's no need to avoid eating things like nuts.

Diverticula that don’t cause any symptoms don’t have to be treated. The treatment options for acute diverticulitis depend on how severe it is. The aim is of treatment is to

• avoid complications from the inflammation or infection,
• relieve acute symptoms,
• stop diverticulitis from occurring again, and
• avoid chronic symptoms.

Infections in diverticulitis are caused by bacteria, so they can be treated with antibiotics. Antibiotics are usually not needed in uncomplicated diverticulitis. But it's important to use them if complications arise or if there’s an increased risk of that happening. Complications may have to be treated in the hospital.

If acute diverticulitis doesn’t improve or someone has ongoing symptoms, the affected part of the bowel can be surgically removed. Because of the associated risks, it’s important to carefully consider the pros and cons of this surgery first. But serious complications like peritonitis require immediate surgery.

For people who have chronic diverticular disease, it can be worth trying to eat more fiber. There’s not yet enough good research to be able to say whether probiotic food products can help. The drug mesalazine or surgery may be considered, too.

When people are ill or need medical advice, they usually go to see their family doctor first. Information about health care in Germany can help you to navigate the German healthcare system and find a suitable doctor. You can use this list of questions to prepare for your appointment.