colitis
Meaning of colitis: The word describes what the lining of the colon looks like, leaving the cause behind it to be worked out separately.
Definition of colitis
Colitis is inflammation of the lining of the colon, the main part of the large intestine. It produces diarrhea, abdominal pain and urgency, sometimes with blood or mucus in the stool, and the pattern depends on the cause and on how much of the colon is involved. The word names a finding rather than one disease.
How colitis is built
- col/o, colon/o Combining form · Greek colon, large intestine
- -itis Suffix · Greek inflammation
A medical term is read from its ending backwards: the suffix first, then the prefix, then the root. See all 223 word parts.
What causes it?
Several quite different processes end in the same inflamed lining, and each tends to leave a characteristic pattern.
| Cause | Pattern that suggests it |
|---|---|
| Infection | Sudden onset after contaminated food, travel or a course of antibiotics; usually settles within days to weeks |
| Ulcerative colitis | Continuous inflammation beginning at the rectum and extending upward, relapsing and remitting over years |
| Crohn disease | Patchy inflammation with normal segments in between, often deeper in the bowel wall |
| Reduced blood supply | Sudden pain followed by bleeding, typically in an older person, at the parts of the colon with the least spare blood supply |
| Radiation | Confined to the area that was treated, appearing during treatment or long afterward |
| Microscopic colitis | Watery diarrhea with a colon that looks entirely normal to the endoscopist |
| Medicines | Includes a nonsteroidal anti-inflammatory drug and the immune activating drugs used against some cancers |
How is the cause identified?
Stool testing comes first, since infection is the most common and the most quickly settled explanation. Direct inspection of the lining through an endoscope shows where the inflammation starts and stops, whether it is continuous or patchy, and whether ulcers are present. A biopsy taken during that examination is what distinguishes several causes that look alike, and it is the only way to identify microscopic colitis, in which the lining appears normal and the abnormality exists only under the microscope. Blood tests, and imaging where a blocked blood supply is suspected, fill in the rest.
Why does the distinction matter?
Because the causes call for entirely different responses, and one can worsen under treatment aimed at another. Infectious colitis is cleared or allowed to resolve; a form of inflammatory bowel disease is a lifelong condition managed by damping the immune response; colitis from reduced blood flow is a circulatory problem. Ulcerative colitis is one specific disease that produces colitis, not a synonym for the finding, and treating every inflamed colon as though it were that disease would be wrong in most cases.
Used in a sentence
Colonoscopy revealed patchy colitis involving the left side of the colon.
Good to know
Colitis is a descriptive finding of colon inflammation and is not synonymous with ulcerative colitis, which is one specific chronic disease that causes colitis among several possible causes.
Word origin
Where “colitis” comes from
Formed from col-, from Greek kolon, meaning colon, and -itis, meaning inflammation.