Changes

*'''Perforation of the gastro-intestinal tract''' due to foreign bodies, [[Intussusception|intussuscepta]], invasive [[Neoplasia - Pathology|neoplasia]], deep ulceration or dehiscence of surgical wounds or biopsy sites. Peritonitis as a result of wound dehiscence is most likely to occur 3-5 days post-operatively.   

*'''Perforation of the gastro-intestinal tract''' due to foreign bodies, [[Intussusception|intussuscepta]], invasive [[Neoplasia - Pathology|neoplasia]], deep ulceration or dehiscence of surgical wounds or biopsy sites. Peritonitis as a result of wound dehiscence is most likely to occur 3-5 days post-operatively.   

*'''Penetration of the abdomen''' by a stick, gunshot or other foreign body.

*'''Penetration of the abdomen''' by a stick, gunshot or other foreign body.

*Rupture of an infected uterus ('''pyometra'''), [[Biliary Tract - Rupture|biliary tract]] or urinary tract.

*Rupture of an infected uterus ('''pyometra'''), [[Biliary Tract Rupture|biliary tract]] or urinary tract.

The bacteria causing septic peritonitis or their products may spread systemically causing sepsis or endotoxaemia.

The bacteria causing septic peritonitis or their products may spread systemically causing sepsis or endotoxaemia.

===Ultrasonography===

===Ultrasonography===

This modality has a high sensitivity for the detection of free fluid in the abdomen and it may be used to identify some specific causes of peritonitis, including abscesses of organs or [[Biliary Tract - Rupture|rupture of the biliary tract]].

This modality has a high sensitivity for the detection of free fluid in the abdomen and it may be used to identify some specific causes of peritonitis, including abscesses of organs or [[Biliary Tract Rupture|rupture of the biliary tract]].

Ultrasound scans can also be used to guide '''abdominocentesis'''.

Ultrasound scans can also be used to guide '''abdominocentesis'''.

Further possible tests include:

Further possible tests include:

*Measurement of '''amylase''' and '''lipase''' where the cause is suspected to be [[Pancreatitis|pancreatitis]]

*Measurement of '''amylase''' and '''lipase''' where the cause is suspected to be [[Pancreatitis|pancreatitis]]

*'''Bile''' where [[Biliary Tract - Rupture|biliary tract rupture]] is suspected.

*'''Bile''' where [[Biliary Tract Rupture|biliary tract rupture]] is suspected.

*'''Creatinine''' and '''potassium''' if the effusion is thought to be a uroabdomen; creatinine levels in a peritoneal sample that are higher than serum concentrations indicate uroperitoneum.

*'''Creatinine''' and '''potassium''' if the effusion is thought to be a uroabdomen; creatinine levels in a peritoneal sample that are higher than serum concentrations indicate uroperitoneum.

*'''Glucose''' and '''lactate''' should be measured; where their values are <2.8 mmol/l and >5.5 mmol/l respectively the inflammation is likely to be septic.

*'''Glucose''' and '''lactate''' should be measured; where their values are <2.8 mmol/l and >5.5 mmol/l respectively the inflammation is likely to be septic.