Recognize the differential diagnosis of acute bloody diarrhea.

Explanation:

Differential includes:

a. Idiopathic inflammatory bowel disease

b. Infectious colitis - EHEC, EIEC, Shigella, salmonella, Campylobacter, Entamoeba histolytica.. History of travel, stool culture positive.

The above two cannot be distinguished in the acute phase by intestinal biopsy.

c. Ischemic colitis - Thumbprinting/pneumatosis intestinalis. Suspect on seeing acidosis of unknown cause and vague abdominal pain. Endoscopic view is diagnostic. Treat by hydration..