Objective: Our objective was to assess how often "outlet obstruction" was the cause of constipation in a tertiary referral population.
Methods: We retrospectively audited the case records of 70 consecutive patients referred to a single gastroenterologist in a tertiary referral motility clinic. Patients were classified by physiological tests of colonic transit, as well as tests of anorectal and pelvic floor function. A subset of 28 patients also underwent a battery of tests to assess the autonomic nervous system supply.
Results: Thirty-six patients had symptoms suggestive of a rectal outlet obstruction syndrome. Thirty seven percent of patients had pelvic floor dysfunction, 27% had slow transit constipation, and 8% had anismus. Fully 55% of those with pelvic floor dysfunction had slow transit in addition. The remaining patients (23%) had at least two of Manning's criteria suggestive of the irritable bowel syndrome. Only four patients had documented abnormalities of autonomic function.
Conclusions: Pelvic floor dysfunction is the most common cause of severe constipation in a tertiary referral motility clinic; slow transit constipation and irritable bowel syndrome occur equally. An algorithmic approach to evaluating patients using clinical features, anorectal functions tests, and assessment of colonic transit facilitates selection of management strategies. Autonomic dysfunction occurs rarely.