Rectal compliance: a critical reappraisal.

Compliance is a widely measured parameter of rectal function. Its value is determined clinically by recording pressure changes associated with volume infusion into a rectal balloon. This paper examines the inherent assumptions of the rectal balloon technique and discusses several of its shortcomings. A stricter definition of rectal compliance is needed, and in vivo compliance should be correlated with the directly measured mechanical properties of the rectal wall.