ABSTRACT
Abdominal distension usually is a sign of an underlying disease process, unless caused by pregnancy or obesity. A serous membrane of mesothelial cells lines the peritoneal cavity and extends to cover the abdominal organs and the associated vasculature and connective tissue. The space between the parietal and visceral peritoneal layers normally contains a small amount of serous fluid. Urine collection within the peritoneal space is uncommon and most often arises from a rupture of the urinary bladder. The presence of free air in the peritoneal space, aside from postoperative situations, is a sign of potentially life-threatening bowel devitalization or perforation. An increase in systemic venous or portal hydrostatic pressures is a major cause. Obstruction in the lymphatic drainage system also promotes peritoneal effusion accumulation. Ascites caused by high venous and capillary hydrostatic pressures is categorized according to the location of the pathology.
