a collection of pus in the space below the diaphragm, usually on the right side, between the liver and diaphragm. Causes include postoperative infection (particularly after the stomach or bowel have been opened) and perforation of an organ (e.g. perforated peptic ulcer). Prompt treatment by antibiotics may be effective, but more frequently the abscess requires surgical drainage.
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an abscess beneath the diaphragm; called also subdiaphragmatic a.Medical dictionary. 2011.