Impact of Inflammatory Activity on Anorectal Function in Patients With Ulcerative Colitis: A Prospective Study

OBJECTIVES: Anorectal symptoms are common in ulcerative colitis (UC), yet the impact of inflammatory activity on anorectal function remains unclear. We evaluated the relationship between inflammatory activity and anorectal function and its effect on symptom development. METHODS: We conducted a prospective observational study on patients with UC and active disease attending our center. Clinical, biochemical, and endoscopic assessments were performed together with high-resolution anorectal manometry (HR-ARM) and rectal electronic barostat testing at two time points: during active disease and 4-6 months after treatment initiation. RESULTS: Thirty-six UC patients and 10 healthy volunteers were included. During active disease, fecal incontinence (FI), urgency, and tenesmus were reported by 66.7%, 91.7%, and 83.3% of patients, respectively. After treatment, symptoms improved; however, a subset of patients remained symptomatic: 32.3% still reported FI, 54.8% urgency, and 51.6% tenesmus. Greater endoscopic and histological activity correlated with lower sensory thresholds and reduced rectal capacity and compliance (all p < 0.05). The Mayo endoscopic subscore correlated inversely with desire to defecate volume (ρ = -0.41, p = 0.014) and maximum tolerated volume (ρ = -0.53, p = 0.001) and positively with anal pressure during the defecatory manoeuver (r = 0.35, p = 0.037). Barostat parameters remained altered after treatment compared with healthy controls, including in patients who achieved histological remission. CONCLUSIONS: Inflammatory activity in UC impairs anorectal function by increasing rectal sensitivity and reducing rectal compliance and capacity, contributing to persistent symptoms. Ongoing dysfunction after remission highlights the need for diagnostic and therapeutic strategies addressing anorectal involvement.