Patterns of High-Resolution Anorectal Manometry in Functional Constipation: A Cross-Sectional Study From India

Background: Functional constipation is a common gastrointestinal disorder, often linked with pelvic floor dysfunction. High-resolution anorectal manometry (HRAM) provides superior detail compared to conventional manometry, but Indian data are limited. Methods: We conducted a crosssectional observational study at a tertiary care gastroenterology center in South India between August 2022 and February 2024. Eighty-seven adult patients fulfilling Rome IV criteria for functional constipation underwent HRAM and balloon expulsion test (BET). The London classification was applied to categorize anorectal dysfunction. Results: The mean age was 45.3 ± 13.7 years; 59.8% were female. Most participants reported incomplete evacuation (71%), straining (74%), and laxative use (72%). HRAM was abnormal in 40.2% and BET abnormal in 35.6%. Based on the London classification, 33.3% had dyssynergic defecation, 10.3% had poor propulsion, 18.4% had combined poor propulsion with dyssynergia, and 11.5% were inconclusive. Anal resting pressure was normal in 72.4%, while 18.4% had hypotension and 9.2% hypertension. Rectal hyposensitivity was noted in a subset of patients. Conclusion: Approximately one-third of Indian patients with functional constipation demonstrated dyssynergic defecation on HRAM. The prevalence of abnormal BET and anal tone disturbances highlights the importance of incorporating HRAM into the diagnostic work-up. These findings provide region-specific insights and support the role of anorectal manometry in guiding biofeedback therapy for constipation in India.