Anal resting pressure decreased significantly after low anterior resection and did not recover in the course of the first year after operation. Moreover, the volume of an air-filled balloon in the neorectum that was required to elicit maximum inhibition of the anal sphincter was significantly less after anterior resection that before operation. These long-term and presumably permanent changes in physiologic behavior of the anoneorectum after low anterior resection provide an explanation for the failure of some patients to regain satisfactory bowel function following that procedure.

Continence after anterior resection is related to an appropriate "sampling" response in the anal sphincter to activity within the neorectum. This in turn, is directly related to length of the residual rectum, which is, therefore, of crucial importance to function.

One-stage restorative proctocolectomy without a defunctioning ileostomy is associated with increased risk to life. Its routine use cannot be recommended.

Thirty consecutive patients had laboratory assessment of anorectal function after rectal excision and stapled coloanal anastomosis for rectal carcinoma. Eleven patients experienced perfect continence but 19 had faecal leakage with or without urgency of defaecation. Median (interquartile range) function was related to the pressures generated in the anal sphincter at rest (good versus poor function: 80 (63-91) versus 51 (23-60) cmH2O, P < 0.01), during maximum squeeze (160 (126-203) versus 102 (58-112) cmH2O, P < 0.01) and during reflex inhibition (58 (23-63) versus 36 (18-54) cmH2O, P < 0.05). Poor function was significantly commoner in women than in men (P < 0.01). These findings suggest that occult damage may have occurred to the anal sphincter before low anterior resection. Careful preoperative evaluation with manometry and endoanal ultrasonography may detect such damage and allow selection of patients for colopouch reconstruction.

Background Closure of an abdominal stoma, a common elective operation, is associated with frequent complications; one of the commonest and impactful is incisional hernia formation. We aimed to investigate whether biological mesh (collagen tissue matrix) can safely reduce the incidence of incisional hernias at the stoma closure site. Methods In this randomised controlled trial (ROCSS) done in 37 hospitals across three European countries (35 UK, one Denmark, one Netherlands), patients aged 18 years or older undergoing elective ileostomy or colostomy closure were randomly assigned using a computer-based algorithm in a 1:1 ratio to either biological mesh reinforcement or closure with sutures alone (control). Training in the novel technique was standardised across hospitals. Patients and outcome assessors were masked to treatment allocation. The primary outcome measure was occurrence of clinically detectable hernia 2 years after randomisation (intention to treat). A sample size of 790 patients was required to identify a 40% reduction (25% to 15%), with 90% power (15% drop-out rate). This study is registered with ClinicalTrials.gov, NCT02238964.