Anechoic fluid in peritoneal space appears black. This could represent hepatic or malignant ascites, peritoneal blood, or in rare case bowel contents or urine.
this is a scan using the curvilinear transducer on an abdominal preset here in the coronal plane at the right mid axillary line at approximately the level of the xiphoid process you can see here the caudal edge of the liver bathed and surrounded by this black hypoechoic fluid these findings represent free fluid in the peritoneal cavity and the possible causes of which could be peritoneal dialysis or blood or ascites
