<prompt> Shoulder pain post laparoscopy is due to:Subphrenic abscessCO2 retentionPositioning of the patientCompression of the lung  <response>: CO2 retention Ref: J Shoulder pain is although a minor complication is exceedingly common and is due to the presence of a significant amount of residual carbon dioxide in the peritoneal cavity, trapped under the diaphragm and causing irritation of the diaphragm and thus referred pain to the shoulder through the phrenic nerve. 