In advanced cases the belly is taut, the umbilicus is flat or everted, and a fluid wave can be elicited. Differentiation from obesity, gaseous distention, pregnancy, or ovarian tumors and other intra-abdominal masses usually is easily made by clinical examination, but scanning techniques or diagnostic paracentesis may occasionally be required. If the cause is uncertain, a diagnostic paracentesis should be done. In most disorders the fluid is clear and straw-colored. Clinical diagnosis may be difficult, as the fluid masks signs of peritonitis.
Survival depends on early, vigorous antibiotic therapy.