Infection *Perforation of part of the gastrointestinal tract is the most common cause of<unk> . Examples include perforation of the distal esophagus (Boerhaave syndrome), of the stomach (peptic ulcer, gastric carcinoma), of the duodenum (peptic ulcer), of the remaining intestine (e.g., appendicitis, diverticulitis, Meckel diverticulum, inflammatory bowel disease (IBD), intestinal infarction, intestinal strangulation, colorectal carcinoma, meconium<unk> , or of the gallbladder (cholecystitis). Other possible reasons for perforation include abdominal trauma, ingestion of a sharp foreign body (such as a fish bone, toothpick or glass shard), perforation by an endoscope or catheter, and anastomotic leakage. The latter occurrence is particularly difficult to diagnose early, as abdominal pain and ileus paralyticus are considered normal in people who have just undergone abdominal surgery. In most cases of perforation of a hollow viscus, mixed bacteria are isolated; the most common agents include Gram-negative bacilli (e.g., Escherichia coli) and anaerobic bacteria (e.g., Bacteroides fragilis). Fecal<unk>  results from the presence of faeces in the peritoneal cavity. It can result from abdominal trauma and occurs if the large bowel is perforated during surgery. * Disruption of the peritoneum, even in the absence of perforation of a hollow viscus, may also cause infection simply by letting micro-organisms into the peritoneal cavity. Examples include trauma, surgical wound, continuous ambulatory peritoneal dialysis, and intra-peritoneal chemotherapy. Again, in most cases, mixed bacteria are isolated; the most common agents include cutaneous species such as Staphylococcus aureus, and coagulase-negative staphylococci, but many others are possible, including fungi such as Candida. * Spontaneous bacterial<unk>  (SBP) is a peculiar form of<unk>  occurring in the absence of an obvious source of contamination. It occurs in people with ascites, including children. * Intra-peritoneal dialysis predisposes to peritoneal infection (sometimes named "primary<unk> " in this context). * Systemic infections (such as tuberculosis) may rarely have a peritoneal localisation. * Pelvic inflammatory disease Non-infection * Leakage of sterile body fluids into the peritoneum, such as blood (e.g., endometriosis, blunt abdominal trauma), gastric juice (e.g., peptic ulcer, gastric carcinoma), bile (e.g., liver biopsy), urine (pelvic trauma), menstruum (e.g., salpingitis), pancreatic juice (pancreatitis), or even the contents of a ruptured dermoid cyst. It is important to note that, while these body fluids are sterile at first, they frequently become infected once they leak out of their organ, leading to infectious<unk>  within 24 to 48 hours. * Sterile abdominal surgery, under normal circumstances, causes localised or minimal generalised<unk> , which may leave behind a foreign body reaction or fibrotic adhesions. However,<unk>  may also be caused by the rare case of a sterile foreign body inadvertently left in the abdomen after surgery (e.g., gauze, sponge). * Much rarer non-infectious causes may include familial Mediterranean fever, TNF receptor associated periodic syndrome, porphyria, and systemic lupus erythematosus. Risk factors * Previous history of<unk>  * History of alcoholism * Liver disease * Fluid accumulation in the abdomen * Weakened immune system * Pelvic inflammatory disease
Peritonitis
Gallstone ileus
Spontaneous bacterial peritonitis
Hemoperitoneum
Appendicitis
Ascites
Cholecystitis
Liver abscess