Probable Isolated Rectal Tuberculosis Presenting as Mild Chronic Proctitis in an Immunocompetent Adolescent: A Diagnostic Pitfall and Mini-Review of the Literature.

Rectal involvement in gastrointestinal tuberculosis (TB) is uncommon and may mimic inflammatory bowel disease or nonspecific proctitis, leading to diagnostic uncertainty. We report the case of an 18-year-old immunocompetent man presenting with chronic increased stool frequency and mucus passage, occasionally blood-streaked, without constitutional symptoms. Colonoscopy revealed nonspecific proctitis. Histopathological examination demonstrated confluent granulomas with Langhans giant cells. Microbiological confirmation including GeneXpert was negative. In view of the strongly suggestive histopathological findings and the endemic setting, a diagnosis of probable isolated TB was made, and anti-tubercular therapy was initiated. Probable rectal TB should be considered in the differential diagnosis of chronic proctitis, even in the absence of systemic features. Histopathology remains crucial, particularly in endemic regions where microbiological tests may be negative.