Incidental intestinal parasitic infections detected during colonoscopy: A case series of hookworm in a Cambodian immigrant and whipworm in Korean patients.

Intestinal helminth infections have become uncommon in Korea but still occur sporadically, either as residual native infections or as imported infections among immigrants. We retrospectively reviewed 4 cases of intestinal helminth infections incidentally identified during colonoscopy at a single academic hospital between January 2019 and March 2026. One Cambodian immigrant had hookworm infection (species-level differentiation between Ancylostoma duodenale and Necator americanus was not possible). Of the 3 Korean patients, 2 had histopathologically confirmed Trichuris trichiura infection, and in 1, T. trichiura infection was suspected endoscopically, but the retrieved organism was not submitted for histopathologic examination. All patients were asymptomatic or had only nonspecific symptoms, and none showed peripheral eosinophilia. Colonoscopy allowed direct visualization and removal of each organism, demonstrating mucosal embedding in T. trichiura infection and firm mucosal attachment of the hookworm in the rectum. Three patients received a single 400-mg oral dose of albendazole; the case without histopathologic confirmation was managed without anthelmintic therapy. Recognition of characteristic endoscopic morphology can guide diagnosis even when histopathologic confirmation is unavailable, and management should be individualized according to diagnostic certainty and clinical context.