1. Inflammatory Bowel Disease Slideshow Pictures
2. Take the Tummy Trouble Quiz
3. Ulcerative Colitis Slideshow Pictures

Medical Author:

Lori Kam, MD

Medical Editor:

Leslie J. Schoenfield, MD, PhD

Leslie J. Schoenfield, MD, PhD

Dr. Schoenfield served as associate professor of medicine and consultant in gastroenterology on the faculty of the Mayo Clinic for seven years. He became a professor of medicine in residence at UCLA from 1972 to 1999 (now emeritus). He was the director of gastroenterology at Cedars-Sinai Medical Center in Los Angeles for 25 years, where he received the chief resident's teaching award, the president's award, and the pioneer of medicine award.

View Full Profile

In this Article

• What is inflammatory bowel disease?
• What are the intestinal complications of IBD?
• Are the intestinal complications of ulcerative colitis and Crohn's disease different?
• Do intestinal ulcers occur in IBD?
• Does gastrointestinal bleeding occur in IBD?
• How do intestinal strictures form in IBD?
• What are the symptoms of intestinal strictures, and how are they diagnosed and treated?
• What are intestinal fistulas?
• What symptoms do fistulas cause and how are they diagnosed and treated?
• What are fissures and how are they treated?
• What is small intestinal bacterial overgrowth (SIBO)?
• Does colon cancer occur in IBD?
• What should be done about polyps in IBD?
• What is toxic megacolon and what are its causes?
• What kind of malabsorption occurs in IBD?
• Intestinal Problems in IBD At A Glance
• Patient Comments: Inflammatory Bowel Disease (IBD) - Treatments
• Patient Comments: Inflammatory Bowel Disease - Experience
• Find a local Gastroenterologist in your town
• Inflammatory Bowel Disease: Intestinal Problems Index

Not all polyps that are found in IBD patients are pre-cancerous or cancerous. Some polyps form as a result of the inflammatory and healing processes. These polyps are called inflammatory polyps or pseudopolyps, and they do not turn into cancer. The only way to make sure that polyps do not have pre-cancerous or cancerous cells, however, is to remove (biopsy) and examine them under the microscope.

Toxic megacolon causes

Toxic megacolon is a widened (dilated) segment of the colon in a patient with severe inflammation of the colon (colitis). The megacolon develops when the lining of the colon is so inflamed that the colon loses its ability to contract properly. When this happens, the propelling (peristaltic) contractions are unable to move the intestinal gas along through the colon. The colon, therefore, accumulates excessive amounts of gas. The gas then increases the pressure on the bowel wall, which causes the colon to dilate.

Toxi megacolon symptoms

Patients with toxic megacolon usually are very ill, with abdominal pain, bloating (distention), and fever. The dilated colon can allow bacteria to leak through the bowel wall into the blood stream (septicemia). With continuing dilation, the inflamed colonic wall becomes at high risk for bursting (perforating) and causing inflammation of the abdominal cavity (peritonitis). Both septicemia and peritonitis are serious infections, which, in some cases, can even lead to death.

Toxic megacolon typically occurs when inflammation of the colon is severe. This complication, however, does not occur exclusively in patients with ulcerative colitis or Crohn's disease. Thus, a toxic megacolon can develop in other types of colitis, such as amebiasis or bacillary dysentery (shigella). Narcotics, codeine, or anti-diarrheal medications such as diphenoxylate (Lomotil) or loperamide (Imodium) can decrease the contractions of the colon and allow excessive gas to accumulate. These medications, therefore, predispose to the development of toxic megacolon and should be avoided during severe episodes (flares) of colitis.