Sudden onset of severe right upper quadrant abdominal pain
Distal pleuritic component +/- radiation to the shoulder
May not have symptoms of PID
Fitz-Hugh-Curtis syndrome
Gallbladder disease
Ogilvie's syndrome
Symptomatic cholelithiasis 
Zollinger-Ellison syndrome
Choledocholithiasis
Dressler's syndrome
Acute cholecystitis