A lower abdominal fluid collection of 2.4 centimeters is roughly 480 milliliters. Normally 1 cm of fluid in the lower abdominal cavity is about 200 milliliters of fluid. If there is 2.4 centimeters of fluid in the lower abdominal cavity, then the amount of fluid is about 480 milliliters. This is only an estimate, and the exact amount of fluid in the abdominal cavity can be measured by ultrasound. There is a small amount of fluid in the normal abdominal cavity, which acts as a lubricant. If the amount of fluid in the abdominal cavity exceeds 200 milliliters, it is usually caused by pathological reasons. It may be related to hypoproteinemia, cirrhosis of the liver, tumor, etc. The patient needs further examination to clarify the cause of ascites. If the lower abdominal fluid is detected and the cause is identified, the patient should be treated accordingly as prescribed by the doctor.