Hello Abdominal tuberculosis can be classified into the Tubercular mesenteric adenitis,intestinal tuberculosis, omental or tubercular peritonitis. The first investigation is blood test which can show increased ESR with raised lymphocytes count.Then an USG should be done to find out any enlarged and matted lymph node,thickening or adhesion of the intestinal wall or any collection of fluid. The next investigation may be CECT abdomen for better delineation of anatomic abnormality or if USG is doubtful. Sometimes there may be formation of cold abscess or mass,then aspiration of pus or USG guided biopsy of mass may be needed.The pus should be sent for test of tuberculosis. A test called Quantiferon gold test may also be advised for diagnosis. Tuberculosis is a communicable disease and mainly spread through droplets.Most communicable is pulmonary tuberculosis.Chances are very very less in abdominal tuberculosis if not associated with pulmonary TB. If there is only abdominal TB no specific precaution is needed. Regards