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What is Diverticular Disease?
Diverticular Disease refers to the “out-pouchings” or “pockets” seen in the wall of the colon. (see picture below) It is often asymptomatic but it can cause bloatedness and cramps in the abdomen associated with passing of hard “pellety” stools like “rabbit droppings”. It becomes problematic when it gives rise to complications such as bleeding, infection (a bit like appendicitis) and blockage of the colon.
Diverticular Disease became a disease entity only after the Industrial Revolution with widespread consumption of polished grains and rice, refined sugar and their products. The decreased intake of dietary fibre is the main cause of the condition. Dietary fibre produces stool bulk, lubricants and stimulants to enable stools to be propelled easily along the colon and rectum. A practical analogy is that of a tube of toothpaste : a new full tube is easily squeezed out while an empty tube requires a lot force and effort to get the toothpaste out. When so much force is applied to the colon, especially when it is not coordinated, after many years, the wall becomes coarse and the inner lining (colonic mucosa) is squeezed through weaknesses in the wall to form pockets (or diverticula) like parts of a balloon being squeezed through the gaps in-between fingers of a pair of hands.
Diverticular disease is very common in Western countries. It is estimated that 60% of UK population above the age of 60 have this condition. An autopsy survey in 1986, found that 19% of Singaporeans above the age of 14 had diverticular disease. This incidence is increasing as the effect of reduced fibre intake takes its toll and as the population gets older. Although the pathology of the disease is identical between Asian and Western populations, an interesting difference is that in Asians, diverticula are more common on the right colon while they are more common on the left colon in the West. The clinical importance is that in Asian patients, diverticulitis (infection and inflammation of a diverticulum) can be mistaken for appendicitis. Although diverticular disease is widespread, only 10% of patients have symptoms and fewer still present with complications such as bleeding, infection and obstruction.
Symptoms of diverticular disease such as abdominal bloatedness and cramps, irregular bowel habit associated with passing pellety stool can be treated with high fibre diet, bulking agent (fibre supplement) and relaxing agents of the colon. As the symptoms can also be caused by colorectal cancer, it is important to exclude cancer by colonoscopy before starting treatment.
Bleeding from diverticular disease can be very scary because it can be massive and it affects mainly older patients. It comes on suddenly and it is painless. Often the patient needs to be admitted to hospital for transfusion and observation. If the bleeding is life threatening or if it occurs in more than two separate occasions, surgery to remove the portion of colon bearing the bleeding diverticulum is required. This procedure is curative but the doctor must first accurately locate the source of the bleeding which can be very difficult : fortunately, we now have tests to help pinpoint the site of bleeding such as colonoscopy, angiogram (X-Ray to visualise blood vessels supplying the colon, small bowel and stomach) and nucleotide scan (radioactive scans)
Diverticulitis (diverticular infection and inflammation) is very much like appendicitis. When a diverticulum is blocked by a hard faecal plug, trapped bacteria sometimes overgrow and cause infection and abscess formation. The body is often successful in limiting this infection and the patient would just present with pain, fever, tenderness in a part of the abdomen and sometimes a palpable lump. This is treated with rest and antibiotics, and the infection usually resolved. If the patient fails to limit the infection there is a risk of peritonitis, surgery is then indicated. Patients with diabetes, or patients who are debilitated, or who are immune suppressed (on steroid, or chemotherapy) have less capacity to limit intra-abdominal infection. Vigilance is required to ensure that when surgery is necessary, it is not carried out too late. For patients who recovered from limited localised diverticulitis, higher fibre diet and symptomatic treatment are necessary. For those with recurrent infection or who live in remote areas and have difficulty accessing proper healthcare facility, pre-emptive surgery must be seriously considered.
Colonic blockage by diverticular disease is now less common. Unrecognised and untreated diverticular disease, when left to sustain repeated inflammation and fibrosis can result in narrowing of the colon. This can cause obstruction and can be difficult to differentiate from colorectal cancer. Treatment is surgical and when the diseased area is removed, the patient is cured.
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General Knowledge & Education