Inflammation of serosal membrane lining abdominal cavity and intraabdominal organ
May be infectious (bacterial, viral, fungal) or sterile (mechanical, chemical)
Etiology
Primary: Hematogenous, spontaneous bacterial<unk>  (SBP)
Secondary: Perforation or trauma, most common
Tertiary: Persistent/recurrent infection, peritoneal dialysis-associated<unk> 
Primary: Hematogenous, spontaneous bacterial<unk>  (SBP)
Secondary: Perforation or trauma, most common
Tertiary: Persistent/recurrent infection, peritoneal dialysis-associated<unk>
Peritonitis
Abdominal aortic aneurysm
Spontaneous bacterial peritonitis
Aortocaval fistula
Appendicitis 
Acute gastroenteritis
Appendicitis
Aortoenteric fisulta