<unk>  is pneumatosis (abnormal presence of air or other gas) in the peritoneal cavity, a potential space within the abdominal cavity. The most common cause is a perforated abdominal organ, generally from a perforated peptic ulcer, although any part of the bowel may perforate from a benign ulcer, tumor or abdominal trauma. A perforated appendix seldom causes a<unk> . Spontaneous<unk>  is a rare case that is not caused by an abdominal organ rupture. This is also called an idiopathic spontaneous<unk>  when the cause is not known. In the mid-twentieth century, an "artificial"<unk>  was sometimes intentionally administered as a treatment for a hiatal hernia. This was achieved by insufflating the abdomen with carbon dioxide. The practice is currently used by surgical teams in order to aid in performing laparoscopic surgery.
Pneumoperitoneum
Chilaiditi syndrome
Hemoperitoneum
Hepatic hydrothorax
Retroperitoneal bleeding
Acute abdomen
Pneumoretroperitoneum
Peritonitis