Conditions and symptoms
What Is Colitis? Bowel Inflammation
Colitis · say it: koh-LY-tisAlso written: inflammation of the colon, pseudomembranous colitis, ulcerative colitis, microscopic colitis
Short answer
Colitis means inflammation of the colon (large bowel), which can cause diarrhea, tummy pain and sometimes blood in the stool.
What it means
Colitis means the lining of the colon, the large bowel, is inflamed. It can cause diarrhea, cramping tummy pain, urgency to open the bowels and sometimes blood or mucus in the stool. There are many causes, including infections, inflammatory bowel disease (ulcerative colitis and Crohn's colitis), reduced blood supply (ischemic colitis) and some medicines.
Labels mention colitis mostly in two ways. Antibiotic labels warn about Clostridioides difficile colitis, which can follow antibiotic use. Some other medicines, including certain cancer immunotherapies and anti-inflammatory medicines, list colitis as a side effect. Severe diarrhea, blood in the stool, high fever or severe pain should be reported urgently.
'Colitis' on its own is a description, not a full diagnosis. Ulcerative colitis is one long-term condition; pseudomembranous colitis usually refers to C. difficile infection.
Where you may see it
- Antibiotic labels under 'C. difficile-associated diarrhea'
- Colonoscopy and biopsy reports
- Immunotherapy medicine leaflets
📄 How it looks on a report
Colonoscopy: Patchy colitis in the sigmoid colon. Biopsies taken.
🙅 What it does not mean
- Colitis does not always mean ulcerative colitis; there are many causes.
- Diarrhea after antibiotics is not always colitis, but severe or bloody diarrhea should be checked.
- Colitis on a report does not by itself mean cancer.
🗒️ Questions to ask your doctor
💊 Medicines whose labels mention “Colitis”
Plain-English explanations of each medicine, from its official FDA label.
- Amoxicillin
a penicillin-class antibacterial medicine that works against bacteria
- Amoxicillin and Clavulanate Potassium
A penicillin-class antibacterial combined with a beta-lactamase inhibitor, as the label describes it
- Ceftriaxone
A broad-spectrum cephalosporin antibiotic, as described on the official FDA label
- Ciprofloxacin
a fluoroquinolone antibacterial medicine
- Clindamycin Phosphate
A lincosamide antibacterial medicine
- Dexamethasone
A corticosteroid, a synthetic adrenocortical steroid medicine that lowers inflammation and suppresses the immune system
- Levofloxacin
an antibiotic of the fluoroquinolone type
- Loperamide
a synthetic antidiarrheal medicine
- Rifampin
an antibiotic of the rifamycin type
🔗 Read more from trusted sources
- “Colitis” on MedlinePlus ↗
US National Library of Medicine
- NCI Dictionary definition ↗
US National Cancer Institute: “colitis”
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General information about a medical word, not advice about your own results. Ask the clinician who ordered the test what it means for you.