<prompt> A 45 year old female presents with 48 hour history of right upper quadrant pain, dyspnea, non-productive cough, fever with chills and rigor. The pain radiates to right shoulder tip. She has history of perforated duodenal ulcer repair 3 weeks ago. Temperature 39.3degC. OE there is acute tenderness over right hypochondrium. CXR shows right sided pleural effusion. DiagnosisAcute pancreatitisSubphrenic abscessAcute cholangitisPyonephrosis  <response>: Ans. b Subphrenic abscessRef: Bailey 26th edition Page 977 Bailey says- Pus Nowhere, Pus Some where- search Pus Under the Diaphragm In a post op case patient lying- most dependent site of abscess formation is Subphrenic Space 