Amebic Colitis

Amebic colitis is an infection by the protozoan parasite Entamoeba histolytica. The disease is especially common in South Africa, Asia, and South/Central America. Encysted amoebae in fecally contaminated food or water are ingested. The capsule dissolves in the small intestine, releasing trophozoites that migrate to the colon and burrow into the mucosa. The infection may spread by direct invasion or hematogenous spread throughout the body. Amebic colitis causes dysentery with frequent bloody mucoid stools, abdominal pain, anorexia and fever. Barium studies reveal aphthous ulcers, deep ulcers, and skip regions with normal intervening mucosa similar to Crohn's. The terminal ileum is characteristically not involved. Complications include strictures, toxic megacolon, fistulas, liver/spleen/brain abscesses, pericarditis, and empyemas. Patients are treated with Metronidazole.