The cause for<unk>  is due to a perforated ulcer located in the duodenum. This occurs when ulcers that have gone untreated for long periods of time, and as a result has burned through the stomach wall. Risk factors for a perforated ulcers include bacterial infection, such as H. pylori, and routine use of nonsteroidal anti-inflammatory drugs. The right lower quadrant pain is caused by peritonitis from exposure to gastrointestinal fluids draining down from the perforation in the right upper quadrant. The exact incidence of<unk>  is unknown.
Valentino's syndrome
Temple–Baraitser syndrome
Catel–Manzke syndrome
Seaver Cassidy syndrome
Bertolotti's syndrome
Nance–Horan syndrome
Neu–Laxova syndrome
Grinspan's syndrome