Detection of free intraperitoneal fluid in healthy young men

Free intraperitoneal fluid is a secondary sign of abdominal disorders. The detection of small volumes of fluid has been documented as a normal finding in women of childbearing age and also in pediatric sonography. However, the finding of free fluid in asymptomatic men has not been similarly documented by sonography. We postulate that with high-frequency linear probes, small volumes of fluid may be detected in asymptomatic men without underlying abdominal disorders.

Ten healthy male volunteers underwent targeted abdominal sonographic examinations after an overnight fast and in an immediate postprandial state. The findings were documented, and representative images were saved for analysis.

We found small slivers or geometric collections of fluid between bowel loops in 4 of the 10 volunteers. No obvious correlation between the detection of fluid and the nutritional or hydration status of the patient was identified.

The findings suggest that small volumes of pelvic free fluid in healthy men can be normal and do not necessarily indicate underlying disorders. The role of free fluid identification as an indicator of major intra-abdominal disorders must be viewed with caution and with careful clinical correlation.