Diverticulosis and diverticulitis
Diverticulosis refers to a condition in which the inner lining of the large intestine bulges out through the outer, muscular layer. These outpouchings arecalled diverticula. Diverticulitis refers to the development of inflammationand infection in one or more diverticula.
The chance of developing diverticula increases with age, so that by the age of 50, about 20-50% of people will have some diverticula. By the age of 90, virtually everyone will have some. Most diverticula measure about 3 mm to justover 3 cm in diameter. Larger diverticula, termed giant diverticula, are quite infrequent, but may measure as large as 15 cm in diameter.
Diverticula are believed caused by overly forceful contractions of the intestine's muscular wall. They are most common in the developed countries of the West (North America, Great Britain, northern and western Europe). This is thought to be due to the diet of these countries, which tends to be low in fiber.A low-fiber diet results in the production of smaller volumes of stool. In order to move this smaller stool, the colon must narrow itself significantly,and does so by contracting down forcefully. This causes an increase in pressure, which, over time, weakens the muscular wall of the intestine and allows diverticular pockets to develop.
The origin of giant diverticula development is not completely understood, although one theory involves gas repeatedly entering and becoming trapped in analready-existing diverticulum, causing stretching and expansion.
The great majority of people with diverticulosis are symptom-free. Many diverticula are accidentally discovered during examinations for other conditions of the intestinal tract.
Some people with diverticulosis have symptoms such as constipation, cramping,and bloating. It is unclear whether these symptoms are actually caused by the diverticula themselves, or whether some other gastrointestinal condition might be responsible. One serious risk of diverticulosis is bleeding. Although an infrequent complication, the bleeding can be quite severe.
Diverticulitis is believed to occur when a hardened piece of stool, undigested food, and bacteria (called a fecalith) becomes lodged in a diverticulum. This blockage interferes with the blood supply to the area, and infection setsin.
An individual with diverticulitis will experience pain and fever. In responseto the infection and the irritation of nearby tissues, the abdominal musclesmay begin to spasm. Walled-off pockets of infection, called abscesses, may appear within the wall of the intestine, or even on the exterior surface of the intestine. When a diverticulum weakens sufficiently, and is filled to bulging with infected pus, a perforation in the intestinal wall may develop. When infected contents of the intestine spill out into the abdomen, the severe infection called peritonitis may occur. Other complications of diverticulitis include the formation of abnormal connections between two organs that normally do not connect (fistulas; for example, between the intestine and the bladder), and scarring outside of the intestine, which obstructs it.
When diverticula are suspected because a patient begins to have sudden rectalbleeding, the location of the bleeding can be studied by performing anangiography, which involves inserting a tiny tube through an artery in the leg, and moving it up into one of the major arteries of the gastrointestinal system. A chemical that shows up on x-ray films is injected, and the area of bleeding is located by looking for an area where the chemical leaks into the interior of the intestine.
In another procedure called endoscopy, a small, flexible scope (endoscope) isinserted through the rectum and into the intestine. The scope usually bearsa fiber-optic camera, which allows the view to be projected onto a televisionscreen.
For cramping pain and constipation believed to be due to diverticulosis, theusual prescription involves increasing fiber in the diet. This can be done byadding supplements of bran or psyllium seed to increase stool volume. Bleeding diverticula can usually be treated by bed rest, with blood transfusion needed for more severe bleeding. In cases of very heavy bleeding, medications that encourage clotting can be injected during the course of a diagnostic angiography.
While there are almost no situations when uncomplicated diverticulosis requires surgery, giant diverticula always require removal. The usual treatment involves removing that portion of the intestine.
Treatment for uncomplicated diverticulitis usually requires hospitalization."Resting the bowel" is a mainstay of treatment, and involves keeping the patient from eating or sometimes even drinking. Therefore, the patient will receive fluids and antibiotics through a needle in the vein (intravenous or IV fluids).
The various complications of diverticulitis need to be treated aggressively,because the death rate from such things as perforation and peritonitis is quite high. Abscesses can be drained of their infected contents by inserting a needle through the skin and into the abscess. When this is unsuccessful, openabdominal surgery will be required to remove the piece of the intestine containing the abscess. Fistulas require surgical repair, including removal of thelength of intestine containing the origin of the fistula, followed by immediate reconnection of the two free ends of intestine. Peritonitis requires opensurgery. Obstructions require immediate surgery to prevent perforation. Massive, uncontrollable bleeding, while rare, may require removal of part or allof the intestine.
When the amount of intestine removed is great, it may be necessary to performa colostomy, which involves pulling the end of the remaining intestine through the abdominal wall, to the outside. This end is fashioned so a bag can fitover it. The patient's waste (feces) collect in the bag. A colostomy may betemporary, in which case another operation will be required to reconnect theintestine. Other times, the patient will have to adjust to living permanentlywith the colostomy bag. Most people with colostomies can have a very activelife.
The prospects for recovery for patients with diverticula are excellent, withonly 20% of patients ever seeking any medical help for their condition. Whilediverticulitis can be a difficult and painful disease, it is usually quite treatable. The prospects are worse for individuals who have other medical problems, particularly those requiring the use of steroid medications. Recovery prospects are also worse in the elderly.
While there is no certain way to prevent the development of diverticula, it is believed that high-fiber diets can help.