A knowledge of intraperitoneal pathways is essential in sonographically evaluating the causes of free intraperitoneal fluid. The right and left paracolic gutters allow free communication of fluid between the abdominal and pelvic cavities,with the right paracolic gutter communicating with Morison's pouch and pericholecystic region. In this case,sonographic demonstration of right upper quadrant fluid with no sonographic or clinical evidence of right upper quadrant pathology prompted the sonographer to evaluate the pelvis for possible etiology.
