Colitis refers to an inflammation of the colon or large intestine. This may be due to an acute process, such as a bacterial infection, or a chronic process such as ulcerative colitis or Crohn’s Disease. Inadequate blood supply to the colon may cause a condition called ischemic colitis, which most commonly involves the left side of the colon.


The most common symptom of colitis is diarrhea. The stool will often contain blood. Bloating, abdominal cramping, and even severe pain may accompany the diarrhea. Severe colitis may result in fever, chills and weight loss.


Colitis can often be diagnosed simply on the basis of a patient’s presenting symptoms and physical examination. Laboratory studies will often reveal an elevated white blood cell count. Appropriate stool studies should be obtained to rule out an infectious cause such as salmonella, shigella, campylobacter orclostridium difficile. Parasitic infections can also cause colitis and are diagnosed by obtaining appropriate stool specimens. Additional testing can include an imaging study of the abdomen, such as a CT scan. Definitive diagnosis may require a colonoscopy with biopsies of the inflamed tissue.


The treatment of colitis is dependent on the cause determined by the diagnostic studies outlined above. Infectious colitis is often self-limited and may not require treatment other than supportive care with fluids and careful observation. Severe infection may require antibiotic therapy. Ischemic colitis is usually self-limited and responds to supportive measures. The treatment of colitis due to Crohn’s Disease or ulcerative colitis is reviewed in the sections outlining those specific conditions.