Abstract
Enteric protozoan infections are a well-documented cause of diarrhea in immunocompromised patients. Special stains on stool specimens are routinely performed in such patients to diagnose these protozoa namely cryptosporidium, microsporidium, and isospora. Duodenal and jejunal biopsies can also be performed to obtain a tissue diagnosis. We report a case of microsporidium enteritis diagnosed on histopathological examination of small bowel resection specimen in a case of perforation peritonitis. The patient was a known HIV-positive on antiretroviral treatment for 2 years and on antitubercular treatment for 3 months. This case report highlights the importance of carefully screening the resection specimens for protozoal infections in immunocompromised individuals. The association of perforation peritonitis and microsporidium is rare. Hence, the possibility that untreated microsporidium infection can lead to perforation cannot be ruled out.