 It is a common finding in patients that have recently undergone biliary surgery or endoscopic biliary procedure.While the presence of air within biliary system is not harmful, this finding may alternatively suggest a pathological process, such as a biliary-enteric anastomosis, an infection of the biliary system, an incompetent sphincter of Oddi, or spontaneous biliary-enteric fistula.In a healthy individual with normal anatomy, there is no air within the biliary tree.