New developments in defecatory studies based on biomechatronics

Abstract Background Defecation is a complex process that is difficult to study and analyze directly. In anorectal disease conditions, the defecation process may be disturbed, resulting in symptoms including fecal incontinence and constipation. The need for physiologically-relevant and easy-to-use diagnostic tests for identifying underlying mechanisms is substantial. Methods We developed a simulated stool named Fecobionics that integrates several tests to assess defecation pressures, shape, orientation and bending during evacuation. Using this novel tool, we present new analytical methods to calculate physiologically relevant parameters during expulsion in normal human subjects. Main findings Data are reported from 28 human subjects with progressively more advanced versions of Fecobionics. A new concept utilizes the rear-front pressure (preload-afterload) diagram for computation of novel defecation indices. Fecobionics obtained physiological data that cannot be obtained with current state-of-the-art technologies. Principal conclusions The study suggests that Fecobionics is effective in evaluation of key defecatory parameters and well positioned as an integrated technology for assessment of anorectal function and dysfunction.