Diverticular Disease of the Colon

Diverticular disease of the colon

Dr Simon Moodie, 2009

www.DrSimonMoodie.com

The words used

The terms diverticular disease or diverticulosis describe the presence of diverticulae in the colon, this is very common and the majority of people with diverticulae in their colon never have any problems from them.

Diverticulitis is a term used when a person who has diverticulosis develops an acutely inflamed diverticulum, this can sometimes require admission to hospital, antibiotics and possibly surgery. 80% of people with diverticulosis will never have an attack of diverticulitis.

How common is diverticulosis?

Diverticulosis is very common, occurring in the western world in 5 percent of people at age 40, in 50 percent by age 60, and in over 65 percent by age 85. The majority of these people who have diverticulosis will never develop a serious complication (bleeding, perforation or diverticulitis). In the Western world diverticulosis occurs in the left colon (towards the end of the bowel), in Africa and the Far East diverticulosis tens to occur in the right colon (further up the bowel). Diverticulosis is becoming increasingly common in the Western world over the last hundred years.

What is diverticulosis?

A diverticulum is a small out-pouching of the bowel wall. People with diverticular disease can have many of these. They are small, usually less than 1cm in size. In diverticulosis the area of the colon affected often also has other changes – the muscles in the bowel wall are stronger and bigger, the bowel often becomes less elastic (distends less) and may be slightly narrowed and more tortuous. There is sometimes minor patchy inflammation of the bowel wall in segments of bowel affected but severe diverticulosis.

What are the symptoms patients may get in uncomplicated diverticulosis (not diverticulitis)?

Because of the changes in the bowel mentioned above, patients may have noticed gradual changes in how their bowel works. These include bloating, flatulence, abdominal pains and irregular bowel movements. Patients may have a variable bowel habit between constipation and diarrhoea or pass “rabbit pellet” like stools.

What are the treatments available in uncomplicated diverticular disease?

Patients with no symptoms. These patients may wish to continue on their current diet, no treatment is needed. However, there is weak evidence from some large studies that a diet higher in fibre (particularly fruit and vegetable, less so with cereal, fibre) may reduce progression of the disease. That is to say, eating more fruit and vegetables (amongst other health benefits) may slightly reduce the chance of developing symptoms from the diverticular disease in the future. A word of caution though, increasing dietary fibre (particularly cereal fibre such as wheat starch/bran) provides more undigested food coming out of the small intestine and arriving in the colon (large intestine) where it is fermented by the millions of bacteria there leading to gas production – most people can cope with this but some notice bloating and discomfort or even pain if they eat too much fibre (see below). Good advice would be to eat a “healthy” diet high in fruit and vegetables, low in red meat, low in saturated fats, high in fish as is promoted widely for many health reasons – but if you are a bloater you may need to limit the fibre a little, particularly the cereal fibre. There is no good evidence that people with diverticulosis should avoid nuts, pips, seeds, sweetcorn, tamato skins and so forth (this used to be suggested to avoid “blocking” the diverticulae, ignore this, there is no evidence it makes any difference).

There is evidence that increasing physical exercise is good (associated with less complications of diverticular disease). There is evidence that obesity is bad (associated with more risk of diverticulitis, especially in the young).

Patients with symptoms. The advice above on diet, activity, obesity still holds if you have symptoms. However, there are other considerations. At the severe end, patients with recurrent symptoms such as pain, bloating , looser stools and periods of pain (and possibly recurrent mild diverticulitis attacks) there is good evidence that a drug called mesalazine (800mg twice a day – either continuously or for 10 days every month) can reduce symptoms in some people. This is an anti-inflammatory drug commonly used to reduce bowel inflammation in other bowel diseases (such as ulcerative colitis). There are also clinical trials showing some benefit from an antibiotic called rifaximin (not available yet in UK) and also one trial showing a benefit from probiotics (lactobacillus casei) in reducing symptoms.

At the less severe end of the spectrum, diet change is likely to be the mainstay of treatment. How to modify you diet will depend on the symptoms that you are trying to improve. As mentioned above, the commonest problem is eating large amounts of fibre with good intentions, but leading to bloating and discomfort. Fibre substitutes such as ispaghula husk (Fybogel) are often prescribed and may help some patients. They promote regular bulky stools and relieve constipation in a similar way to dietary fibre. They do lead to some bloating and discomfort in some people though (but less than a high cereal fibre diet). They should be seen as an alternative way of taking fibre out of choice if fruit and vegetable dietary fibre is not liked or well tolerated. As discussed above, though, the evidence is that high fibre only slightly reduces long term complications in diverticular disease and immediate quality of life is important – don’t make yourself bloated and uncomfortable. Bloated patients often do best with a low fibre diet, no Fybogel, but sometimes a small daily dose of a non-formentable (non-bloating) laxative such as movicol if they are constipated.

Diverticulitis

Diverticulitis develops in 10-25% of patients with diverticulosis at some point. Diverticulitis can be managed medically in 70% of people but up to 30% may need surgery (often because of perforation or abscess formation). Symptoms are usually a short history of abdominal pain and tenderness (localised to left lower quadrant of abdomen in 90% of cases), fever (60-100% of cases). Patients may also get nausea, vomiting and sometimes looser stools or constipation. Treatment is with antibiotics (usually either co-amoxiclav (“augmentin”) or a combination of ciprofloxacin and metronidazole) taken as an outpatient in many. However, some patients require admission to hospital and intravenous antibiotics, with bowel rest by drinking only clear liquids. There is a risk of perforation and other complications that can be serious and occasionally life threatening. If you develop an attack of diverticulitis you should see your GP urgently for an assessment and to start treatment quickly.

Of those that get better on antibiotics alone, there is a risk of further attacks of diverticulitis. Surgery electively to remove the segment of bowel affected should be considered after two attacks of diverticulitis but this choice depends on many factors including the patient’s general health, age and hence the risks of surgery. Recurrence after the segment of bowel affected by diverticulosis has been removed is rare.