Colonoscopy with evaluation of the terminal ileum is the gold standard in the diagnosis of<unk> . However, in most cases, a limited evaluation of the distal colon with flexible sigmoidoscopy is sufficient. Endoscopic findings may include loss of vascular pattern, erythema, edema, erosions, ulcers, exudates, granularity, and bleeding. Biopsies should be taken even in endoscopic findings are normal, as inflammation may not be immediately apparent and may only be seen on histology (microscopic colitis). Symptoms of nausea, vomiting and epigastric pain may suggest involvement of the upper gastrointestinal tract. If present, evaluation with upper endoscopy is warranted. There are no stool tests or blood tests specific for<unk> . However, diagnostic evaluation should include ruling out infectious causes for diarrhea and colitis. Stool studies should include: Clostridioides difficile toxin, bacterial culture, ova and parasites. Testing for CMV infection should be considered. Fecal calprotectin may be helpful, and is very sensitive and specific for inflammation in the intestines. Elevations in fecal calprotectin correlate with the extent of intestinal inflammation. Computed tomography (CT) imaging may show evidence of colitis, though the sensitivity is relatively low (50%). Free air in the peritoneum indicates bowel perforation. Abdominal imaging may be necessary to rule out toxic megacolon or perforation. Though rare, gastrointestinal metastases (rare) should be considered as a cause of symptoms.
Checkpoint inhibitor induced colitis
Radiation enteropathy
Radiation colitis
Alkylating antineoplastic agent
Lymphocytic colitis
Microscopic colitis
Immunosuppressive drug
NSAID hypersensitivity reactions