Anorectal dysfunction in patients with ulcerative colitis: impaired adaptation or enhanced perception?

Background Rectal disorders during ulcerative colitis (UC) drastically alter the quality of life and may result from an impairment of rectal perception and compliance. This study aims to assess anorectal disorders in patients with mild-to-moderate UC. Methods Anal pressures and the rectal responses to phasic rectal isobaric distension in 10 patients with mild-to-moderate UC were prospectively compared with those in 10 healthy volunteers (HVs). Key Results The patients in each group were similar regarding age, gender, and delivery. In the resting state, the anal canal pressures were similar between the groups. Only the squeeze pressures of the lower anal canal were significantly lower in UC patients than in HVs. During phasic isobaric distension, rectal sensitivity was similar between the groups, whatever the step of distension. Isobaric rectal distension resulted in a significant decrease of the rectoanal inhibitory reflex and a decrease in rectal tone and a significant drop in rectal compliance in UC patients compared with HVs. Conclusions & Inferences Patients showing mild-to-moderate UC experience rectal compliance and innervation disorders without a significant change in rectal sensitivity. The findings of this work suggest impairment not only of the properties of the rectal wall but also of intrinsic innervation. Repeated evaluation over time may be helpful for analyzing the reversibility of the process after healing.