"Post-operative free gas is non-specific and can be a normal postoperative finding or indicate serious pathology such as a bowel perforation. The differentiation between these two entities is primarily clinical and the job of the radiologist is to help put the gas into context for the clinical team:"
"Postoperative free intraperitoneal gas is also referred to as postoperative pneumoperitoneum 1."
"On abdominal radiographs, signs of pneumoperitoneum may be visible (eg. Rigler sign)."
"CT is more sensitive than radiographs for detection of postoperative free gas; non-significant postoperative free gas has been detected rarely on CT up to postoperative day 18 8"