(Subphrenic abscess) Following Laparotomy it has been established that half of all patients develop some postoperative pulmonary collapse. This patient has pain in epigastrium, which exacerbates by deep breathing; hence, he will have some respiratory compromise adding to retained secretions.Leucocytosis, epigastric pain, local paralytic ileus in LUQ in the form of an air-fluid level there, with the reduced breath sounds at LLZ of lungs in a postoperative patient direct towards a infective subdiaphragmatic pathology, in turn affecting LLZ in form of Fleischner's plate atelectasis, i.e., most likely to be subphrenic abscess. However, the subsegmental or plate-like atelectasis as such appears about 24 hrs post-operatively and resolves in 2-3 days. Here the subdiaphragmatic abscess would be impoant.