Usually only large amounts of intraperitoneal fluid can be detected on the plain abdominal film. The fluid causes a generalized haziness or "ground glass" appearance to the abdomen. The bowel loops may be separated by interposed fluid and assume a central location as they float to the highest point of the abdomen. The liver edge and the tip of the spleen may be obscured. Smaller amounts of fluid may preferentially occupy the pelvis, causing a more focal soft tissue haziness and obscuring the urinary bladder.

Ultrasound and CT are more sensitive methods of detecting small amounts of ascites. Ultrasound may show fluid collecting in the flanks and pelvis. CT can detect small amounts of ascites in the cul-de-sac or perihepatic space. The presence of soft tissue masses on CT in association with ascites may be a clue as to a malignant etiology.

A second example of ascites obscuring the liver edge and displacing bowel from the flanks is included (Film .2).