Diverticulitis refers to the development of inflammation and infection in one or more diverticula. Diverticula are outpouchings or bulges which occur when the inner, lining layer of the large intestine (colon) bulges out (herniates) through the outer, muscular layer. The presence of diverticula indicates a condition called diverticulosis.
Diverticula tend to occur most frequently in the last segment of the large intestine, the sigmoid colon. They occur with decreasing frequency as an examination moves toward the beginning of the large intestine. The chance of developing diverticula increases with age, so that by the age of 50, about 20–50% of all people will have some diverticula. By the age of 90, virtually everyone will have developed some diverticula. Most diverticula measure 3–30 mm in diameter. Larger diverticula, termed giant diverticula, are quite infrequent, but may measure as large as 15 cm in diameter.
The great majority of people with diverticulosis will remain symptom-free. Many diverticula are quite accidentally discovered during examinations for other conditions of the intestinal tract.
Causes & symptoms
Diverticula are believed to be caused by overly forceful contractions of the muscular wall of the large intestine. As areas of this wall spasm, they become weaker and weaker, allowing the inner lining to bulge through. The anatomically weakest areas of the intestinal wall occur next to the blood vessels that course through the wall, so diverticula commonly occur in these locations.
Diverticula are most common among the populations of the developed countries of the West (North America, Great Britain, and northern and western Europe). This is thought to be due these countries'diets , which tend to be quite low in fiber. A diet low in fiber results in the production of smaller volumes of stool. In order to move this smaller stool along the colon and out of the rectum, 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.
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 sets in.
Diverticulitis is three times more likely to occur in the left side of the large intestine. Since most diverticula are located in the sigmoid colon (the final segment of the large intestine which empties into the rectum), most diverticulitis also takes place in the sigmoid. The elderly have the most serious complications from diverticulitis, although very severe infections can also occur in patients under the age of 50. Men are three times more likely than women to be stricken with diverticulitis.
An individual with diverticulitis will experience pain (especially in the lower left side of the abdomen) and fever . In response to the infection and the irritation of nearby tissues within the abdomen, the abdominal muscles may begin to spasm. About 25% of all patients with diverticulitis will have some rectal bleeding, although
this rarely becomes severe. 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 the infected contents of the intestine spill out into the abdomen, a severe infection called peritonitis may occur. Peritonitis is an infection and inflammation of the lining of the abdominal cavity, the peritoneum. Other complications of diverticulitis include the formation of abnormal connections, called fistulas, between two organs which normally do not connect (for example, the intestine and the bladder), and scarring outside of the intestine that squeezes off and obstructs a portion of the intestine.
When diverticula are suspected because a patient begins to have sudden rectal bleeding, the location of the bleeding can be studied by performing angiography. Angiography involves inserting a tiny tube (catheter) through an artery in the leg, and moving it up into one of the major arteries of the gastrointestinal system. A dye (contrast medium) which will show up on x-ray films, is injected into the catheter, and the area of bleeding is located by looking for an area where the contrast is leaking into the interior (lumen) of the intestine.
A procedure called colonoscopy provides another method for examining the colon and locating the site of bleeding. In colonoscopy, a small, flexible scope (colonoscope) is inserted through the rectum and into the intestine. A fiber-optic camera that projects to a nearby television screen is mounted in the colonoscope, which allows the physician to view the interior of the colon and locate the source of bleeding.
Diagnosis of diverticulitis is not difficult in patients with previously diagnosed diverticulosis. The presence of abdominal pain and fever in such an individual would make the suspicion of diverticulitis quite high. Examination of the abdomen will usually reveal tenderness to touch, with the patient's abdominal muscles contracting strongly to protect the tender area. During a rectal exam, a doctor may be able to feel an abnormal mass. Touching this mass may prove painful to the patient.
When a practitioner is suspicious of diverticulitis as the cause for the patient's symptoms, he or she will most likely avoid the types of tests usually used to diagnose gastrointestinal disorders. These include barium enema and colonoscopy (although colonoscopy may have been used earlier to diagnose the diverticulosis). The concern is that the increased pressure exerted on the intestine during these exams may increase the likelihood of intestinal perforation. After medical treatment for the diverticulitis, these examinations may be performed in order to learn the extent of the patient's disease.
Treatment for uncomplicated diverticulitis usually requires hospitalization, but some physicians will agree to try treatment at home for very mildly ill patients. These patients will be put on a liquid diet and receive oral antibiotics. Although relaxation, guided imagery , and acupuncture treatment may be helpful in alleviating pain symptoms, a course of antibiotics is necessary to treat the infection itself.
An infusion of herbs with anti-inflammatory and soothing properties, such as Mexican yam (Dioscorea villosa ), German chamomile (Matricaria recutita ), marsh mallow (Althaea officinalis ), and calamus (Acorus calamus, or sweet flag) may be helpful in treating the inflammation of diverticulitis. Ginger (Zingiber officinale ) can also be helpful in relieving gastrointestinal gas that may be symptomatic of the disorder.
"Resting the bowel" is a mainstay of treatment, and involves keeping the patient from eating or sometimes even drinking anything by mouth. Therefore, a patient hospitalized for diverticulitis will need to receive fluids through a needle in the vein (intravenous or IV fluids). Antibiotics will also be administered through the IV. In cases of severe bleeding (hemorrhaging), blood transfusion may be necessary. Medications that encourage clotting may also be required.
While there are almost no situations when uncomplicated diverticulosis requires surgery, giant diverticula always require removal. This is due to the very high chance of infection and perforation of these diverticula. When giant diverticula are diagnosed, the usual treatment involves removing that portion of the intestine.
The various complications of diverticulitis need to be treated aggressively, because the death rate from problems such as perforation and peritonitis is quite high. Abscesses can be drained of their infected contents by inserting a needle through the skin of the abdomen and into the abscess . When this is unsuccessful, open abdominal surgery will be required to remove the piece of the intestine containing the abscess. Fistulas require surgical repair, including the removal of the length of intestine containing the origin of the fistula, followed by immediate reconnection of the two free ends of intestine. Peritonitis requires open surgery. The entire abdominal cavity is cleaned by being irrigated (washed) with a warmed sterile saltwater solution, and the damaged piece of intestine is removed. Obstructions require immediate surgery to prevent perforation. Massive, uncontrollable bleeding, while rare, may require removal of part or all of the large intestine.
During any of these types of operations, the surgeon must make an important decision regarding the quantity of intestine that must be removed. When the amount of intestine removed is great, it may be necessary to perform a colostomy. A colostomy involves pulling the end of the remaining intestine through the abdominal wall, to the outside. This bit of intestine is then fashioned so that a bag can be fit over it. The patient's waste (feces) collect in the bag, because the intestine no longer connects with the rectum. This colostomy may be temporary, in which case another operation will be required to reconnect the intestine, after some months of substantial healing has occurred. Other times, the colostomy will need to be permanent, and the patient will have to adjust to living permanently with the colostomy bag. Most people with colostomies are able to go on with a very active life.
Occasionally, a patient will have such severe diverticular disease that a surgeon recommends planning ahead, and schedules removal of a portion of the colon. This is done to avoid the high risk of surgery performed after a complication has set in. Certain developments will identify those patients who are at very high risk of experiencing dangerous complications, such as those with a history of diverticulitis.
Surgery for chronic (recurring) diverticulitis remains controversial. Some surgeons say that surgery prevents recurrence of problems, while others say it does not. In 2002, a report to family physicians said that elective surgery in cases of severe diverticulitis produces good outcomes and low rates of recurrence. However, patients should be cautioned about possible postoperative complications such as bleeding, abscess, and bowel obstruction. The risk of depends on functional bowel symptoms before surgery.
The prognosis for people with diverticula is excellent, with only 20% of such patients ever seeking any medical help for their condition.
While diverticulitis can be a difficult and painful disease, it is usually quite treatable. Prognosis is worse for individuals who have other medical problems, particularly those requiring the use of steroid medications, which increase the chances of developing a serious infection. Prognosis is also worse in the elderly.
While there is no absolutely certain way to prevent the development of diverticula, it is believed that high-fiber diets may help. Foods that are recommended for their high fiber content include whole grain breads and cereals, and all types of fruits and vegetables. Most experts suggest that individuals take in 20–35 grams of fiber daily. If this is not possible to achieve through diet, an individual may supplement with fiber products that are mixed into juice or water.
Hoffman, David. The Complete Illustrated Herbal. New York: Barnes & Noble Books, 1999.
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Cerda, James J., et al. "Diverticulitis: Current Management Strategies." Patient Care 31, no. 12 (July 15, 1997): 170+.
Cunningham, Mark A., et al. "Medical Versus Surgical Management of Diverticulitis in Patients Under Age 40." American Journal of Surgery 174, no. 6 (December 1997): 733+.
"Diet for Diverticulosis." Consumer Reports on Health 8, no. 11 (November 1996): 132.
"Keeping Diverticulosis Silent." Berkeley Wellness Letter 12, no. 4 (January 1996): 6+.
Walling, Anne D. "Surgical Treatment of Severe Diverticular Disease." American Family Physician (June 1, 2002): 2366.
National Digestive Diseases Information Clearinghouse. 2 Information Way, Bethesda, MD 20892-3570. (301) 654-3810. http://www.niddk.nih.gov/health/digest/nddic.htm.
Teresa G. Odle
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Diverticulitis is a condition in which tiny outpouchings of the colon (large intestine) become inflamed and infected. These outpouchings are called diverticuli; the term that describes the presence of many of these diverticuli is “diverticulosis.” Together, these conditions are referred to as diverticular disease.
People can have diverticulosis without having any symptoms, and not all people with diverticulosis go on to develop diverticulitis. About 10% of people over 40 have diverticulosis; of these, about 10-25% will eventually develop diverticulitis in one or more of the diverticular pouches.
Although the cause of diverticular disease is not completely understood, a low-fiber diet is thought to be an important factor. People who live in industrialized countries where low-fiber diets are prevalent (the United States, Great Britain, Australia) have higher rates of diverticular disease than do individuals living in arts of the world higher-fiber diets are common (such as Asia). Low-fiber diets often result in some degree of constipation, requiring straining during defectation. This straining causes increased pressure in the colon, which may result in the development of diverticuli. When a bit of stool blocks the diverticulum, bacteria within the pouch may have the opportunity to grow, resulting in the infection of diverticulitis.
While some people can have diverticulosis without any recognizable symptoms, other people have clear-cut discomfort related to the condition, including bloating, cramps, and constipation. Diverticulitis causes more severe symptoms, such as
- Severe abdominal pain and cramping
- Fever and chills
- Nausea and vomiting
- Fistula formation (most commonly between the colon and the bladder)
- Intestinal obstruction
Severe complications of untreated diverticulitis can result in a walled off, pus-filled area of infection called an abscess. Perforation of the diverticular pouch, may also occur, resulting in leakage of intestinal contents into the abdomen, and peritonitis (a severe and life-threatening infection of the lining of the abdominal cavity.
Asymptomatic cases of diverticulosis are often diagnosed during medical exams (such as colonoscopy)
Colostomy— A temporary or permanent diversion in which the colon opens to the outside of the body through a hole (stoma). Stool is collected outside of the body in a bag attached to the colostomy.
Fistula— An abnormal connection between two organs, or between an organ and the outside of the body.
Stoma— An opening in the body fashioned by a surgeon.
done for screening or other purposes. Diverticular disease can also be diagnosed with barium enema or CT scan. If bleeding is suspected, a radionuclide angiogram may be ordered, in order to evaluate the extent of bleeding.
Treatment of diverticulosis starts with increasing fiber in the diet. However, once diverticulitis sets in, dietary interventions are insufficient. Diverticulitis must be treated with hospitalization, intravenous antibiotics (such as ampicillin, piperacillin, ciprofloxacin, and cefox-itin), nasogastric tube and suction to remove accumulating gastric juices (in the case of intestinal obstruction), and bowel rest (taking nothing by mouth or staying on a liquid diet until the intestine has healed sufficiently).
In some cases, surgical intervention will be required. Surgery may utilize a traditional open incision (laparotomy) or may be achieved through minimally invasive, laparoscopic techniques (laparoscopy), using several tiny incisions, a lighted fiberoptic scope, and miniaturized surgical instruments. The section of the colon with the infected diverticuli will be removed (bowel resection). In uncomplicated cases of diverticulosis, the two remaining ends of intestine will be attached to each other, restoring an intact gastrointestinal tract.
When severe inflammation and infection are present, however, the remaining ends cannot be rejoined immediately. The remaining end of the colon closest to the rectum will be closed off temporarily. The end of the colon that is continuous with the small intestine will be brought to the surface of the abdomen and connected up with a temporary stoma (hole) through the abdomen. This allows stool to exit through this colostomy, into a special bag that can be put over the stoma to catch the feces. After a few months, a second operation will be performed to close the stoma and reattach the ends of the colon to each other.
Feldman, M., et al. Sleisenger & Fordtran’s Gastrointestinal and Liver Disease. 8th ed. St. Louis: Mosby, 2005.
Khatri, V. P., and J. A. Asensio. Operative Surgery Manual. 1st ed. Philadelphia: Saunders, 2003.
Townsend, C. M., et al. Sabiston Textbook of Surgery. 17th ed. Philadelphia: Saunders, 2004.
Rosalyn Carson-DeWitt, MD
DNR order seeDo not resuscitate order (DNR)
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