*Perforated duodenal ulcer – The most common cause of rupture in the abdomen. Especially of the anterior aspect of the first part of the duodenum. *Perforated peptic ulcer *Bowel obstruction *Ruptured diverticulum *Penetrating trauma *Ruptured inflammatory bowel disease (e.g., megacolon) *Necrotising enterocolitis/pneumatosis coli *Bowel cancer *Ischemic bowel *Steroids *After laparotomy *After laparoscopy *Breakdown of a surgical anastomosis *Bowel injury after endoscopy *Peritoneal dialysis (PD), although the prevalence of<unk>  is estimated to be less than 4% among people with PD in a more recent study in the United Kingdom. *Vaginal insufflation (air enters via the fallopian tubes; e.g., water-skiing, oral sex) *Colonic or peritoneal infection *From chest (e.g., bronchopleural fistula) *Non-invasive PAP (positive airway pressure) can force air down duodenum as well as down trachea.
Pneumoperitoneum
Chilaiditi syndrome
Hemoperitoneum
Hepatic hydrothorax
Retroperitoneal bleeding
Acute abdomen
Pneumoretroperitoneum
Peritonitis