Evidence-based approach to diagnosis and management of abdominal tuberculosis

Abdominal tuberculosis is an ancient problem with modern nuances in diagnosis and management. The two major forms are tuberculous peritonitis and gastrointestinal tuberculosis (GITB), while the less frequent forms are esophageal, gastroduodenal, pancreatic, hepatic, gallbladder and biliary tuberculosis. The clinicians need to discriminate the disease from the close mimics: peritoneal carcinomatosis closely mimics peritoneal tuberculosis, while Crohn's disease closely mimics intestinal tuberculosis. Imaging modalities (ultrasound, computed tomography, magnetic resonance imaging and occasionally positron emission tomography) guide the line of evaluation. Research in diagnostics (imaging and endoscopy) has helped in the better acquisition of tissue for histological and microbiological tests. Although point-of-care polymerase chain reaction-based tests (e.g. Xpert Mtb/Rif) may provide a quick diagnosis, these have low sensitivity. In such situations, ancillary investigations such as ascitic adenosine deaminase and histological clues (granulomas, caseating necrosis, ulcers lined by histiocytes) may provide some specificity to the diagnosis. A diagnostic trial of antitubercular therapy (ATT) may be considered if all diagnostic armamentaria fail to clinch the diagnosis, especially in TB-endemic regions. Objective evaluation with clear endpoints of response is mandatory in such situations. Early mucosal response (healing of ulcers at two months) and resolution of ascites are objective criteria for early response assessment and should be sought at two months. Biomarkers, especially fecal calprotectin for intestinal tuberculosis, have also shown promise. For most forms of abdominal tuberculosis, six months of ATT is sufficient. Sequelae of GITB may require endoscopic balloon dilatation for intestinal strictures or surgical intervention for recurrent intestinal obstruction, perforation or massive bleeding.