Sequential assessment of bowel function and anorectal physiology after anterior resection for cancer: a prospective cohort study

Aim: to investigate changes in bowel function and anorectal physiology (ARP) after anterior resection for colorectal cancer.Methods: patients were recruited from November 2006 to September 2008. Cleveland Clinic Incontinence (CCI) scores and stool frequency were determined by patient questionnaires before surgery (t0 ) and at three (t3 ), six (t6 ), nine (t9 ) and 12 (t12 ) months after restoration of intestinal continuity. ARP measurements were recorded at t0 , t3 and t12 . Endoanal ultrasound was performed at t0 and t12 .Results: eighty-nine patients were included in the study. CCI score increased post-operatively then normalised, whereas stool frequency did not change. Patients who had neoadjuvant radiotherapy or lower anastomoses had increased incontinence and stool frequency in the post-operative period, whereas those with defunctioning stomas or open surgery had increased stool frequency alone. Maximum resting pressure, volume at first urge and maximum rectal tolerance were reduced throughout the post-operative period. Radiotherapy, lower anastomosis and defunctioning stoma (but not operative approach) altered manometric parameters post-operatively. Maximum tolerance correlated with incontinence and first urge with stool frequency. Anterior internal anal sphincter thickness decreased post-operatively.Conclusions: incontinence recovers in the first year after anterior resection. Radiotherapy, lower anastomosis, defunctioning stoma and open surgery negatively influence bowel function. ARP may be useful if bowel dysfunction persists beyond 12 months.</p