Inflammation is the body's nonspecific response to a wide variety of abnormalities. The inflammatory response includes increased blood flow through and leakiness of the blood vessels at the site of the abnormality. White blood cells enter the site and attack the provocative agents. When inflammation occurs in the colon, the condition is called "colitis." Several conditions cause an inflamed colon. Treatment varies according to the medical disorder causing the condition.
A colonic diverticulum is the outpouching of bowel lining through a weak spot in the muscle layers of the intestinal wall. These tiny sacs are subject to obstruction by bits of stool and subsequent infection. The nearby colon tissue -- most commonly on the left side -- becomes inflamed, causing pain and fever. Walled-off pockets of infection, or abscesses, may develop. Initial treatment includes antibiotics, a diet to rest the colon and pain medications. For people in whom the condition worsens despite medical treatment or who develop leakage from the colon into the abdominal cavity or blockage of the bowel, surgery may be necessary to remove the affected part of the intestine.
Ulcerative colitis is a form of inflammatory bowel disease that affects the colon and rectum. The disease may be present in part or all of the colon. The extent and severity of disease determine the treatment choices. For mild disease in only the lower colon or rectum, medications such as sulfasalazine (Azulfidine) or mesalamine (Pentasa) may be taken by mouth. Mesalamine may also be administered by suppository or enema, as may be hydrocortisone foam. Disease that affects areas of the colon closer to the small bowel are treated with medicines taken by mouth. More severe disease may require a combination of drugs, such as sulfasalazine (Azulfidine), steroids, azathioprine (Imuran) and mercaptopurine (6MP). Infliximab (Remicade) is a man-made antibody that interrupts the inflammatory process and is injected over 4 to 6 weeks in people who are resistant to other therapy. Complications of ulcerative colitis, such as bowel obstruction, a hole in the colon and cancer, require surgical removal of the colon.
Crohn disease is also a form of inflammatory bowel disease. It may involve any part of the intestinal tract as well as other parts of the body, such as the joints, eyes and skin. When the disease is mild and limited mainly to the colon, sulfasalazine, budesonide (Entocort EC) or other steroids may be taken by mouth. More severe disease is treated with oral prednisone and followed by azathioprine or mercaptopurine. Infliximab is effective in some people who are not helped by or cannot tolerate other medications. Surgery is used to relieve complications of Crohn disease, such as a hole in the bowel and blockage.
The normal colon contains millions of natural, healthy bacteria. Treatment of any disease with an antibiotic may have the unintended consequence of killing those bacteria and allowing harmful germs to overgrow and inflame the colon. The most common of those harmful germs is Clostridium difficile, and the disease that results is known as antibiotic-associated colitis. Mild antibiotic-associated colitis is treated with metronidazole (Flagyl) taken by mouth. Moderate disease is treated with oral vancomycin (Vancocin). More severe disease requires the combination of oral vancomycin, metronidazole administered through a vein and vancomycin enemas. Surgery is required for severe complications, such as rupture of the bowel. Chronic disease may be treated with ingestion of fecal pellets donated by normal volunteers.