Fecal Total Solids, 72-Hour Stool Collection

What This Test Measures

Total solids refers to the portion of stool that is not water—this includes undigested food residue, bacteria, and other solid materials. Because stool water content varies from day to day, a 72-hour collection is used to get a more reliable average of your stool's solid makeup.

Why a 72-Hour Collection Is Used

Stool output and consistency can change throughout the day, so a single sample may not represent your usual pattern. Collecting all stool produced over 72 hours (three days) gives your care team a more complete picture of how much solid material you are producing and passing.

How the Sample Is Collected

Your care team will give you a special container and instructions for collecting and storing every bowel movement over the three-day period. It is important to follow the collection directions carefully, keep the sample cool as instructed, and avoid contaminating it with urine or toilet paper unless told otherwise.

What the Results Can Help Evaluate

Results are generally interpreted together with other stool tests and your symptoms. Changes in stool solid content can be seen with conditions that affect digestion, absorption, or the amount of water in the stool. Your clinician will explain what your result means in the context of your overall health.