Abstract
Tuberculosis (TB) is endemic in Sri Lanka but is associated with a comparatively low overall disease burden. Pulmonary TB is the most common manifestation among immunocompetent individuals, whereas peritoneal TB is rare and presents significant diagnostic challenges due to nonspecific clinical features such as abdominal distension, chronic diarrhoea, and ascites. We report the case of a 33-year-old immunocompetent male who presented with progressive, painless abdominal distension. A diagnostic mini-laparotomy with omental biopsy confirmed peritoneal TB. Anti-tuberculous therapy was initiated, resulting in complete resolution of ascites on follow-up. This case highlights the diagnostic difficulty of abdominal TB in immunocompetent patients and emphasizes the importance of maintaining a heightened suspicion and initiating early treatment to improve clinical outcomes.