Severe or increasing abdominal pain with progressive signs of deterioration

Bile-stained or feculent vomitus

Involuntary abdominal guarding/rigidity

Rebound abdominal tenderness

Marked abdominal distension with diffuse tympany

Signs of acute fluid or blood loss into the abdomen

Significant abdominal trauma

Suspected surgical cause for the pain

Abdominal pain without an obvious etiology