Diagnosis of<unk>  requires radiographic studies. Classic radiographic findings are known as Rigler's triad: * pneumobilia (air within the biliary tree) * evidence of small bowel obstruction * radiopaque<unk>  on abdominal radiograph
Gallstone ileus
Acute pancreatitis
Chronic pancreatitis
Ascending cholangitis
Biliary colic
Pancreatic abscess
Biliary fistula
Spontaneous bacterial peritonitis