A valid and reliable tool to quantify stool output in tube-fed patients.

A major problem in determining whether diarrhea exists in tube-fed patients is the quantification of stool output. On the basis of this need a stool output assessment tool was developed and tested for validity and reliability. Interrater reliability and construct validity were determined by using staff nurses' and principal investigators' observations. Observers blindly rated the bowel movement (BM) on size and consistency and on whether the BM was thought to represent "diarrhea." Interrater reliability was found to be significant. Stool output scores were determined by using a 24-hour output form that assessed stool size, consistency, and frequency. Content validity was established as well as concurrent and construct validity.