OBJECTIVE To describe the sonographic appearance of normal anal sphincter anatomy and sphincter defects evaluated with a conventional 5 MHz convex transducer placed on the perineum. DESIGN Prospective, single-blind study. SETTING Department of Obstetrics and Gynecology, University of Michigan Medical Center, USA. POPULATION Twenty-five women with symptoms of faecal incontinence, 11 asympt...

OBJECTIVE To summarise current knowledge of Internal anal sphincter. BACKGROUND The internal anal sphincter (IAS) is the involuntary ring of smooth muscle in the anal canal and is the major contributor to the resting pressure in the anus. Structural injury or functional weakness of the muscle results in passive incontinence of faeces and flatus. With advent of new assessment and treatment mod...

Introduction Fetal incontinence due to agenesis or damage of the sphincter apparatus is a major cause of social dilemma in the pediatric, adolescent and adult population. The anal sphincter consists of an internal sphincter which is a smooth muscle complex and is responsible among other factors for the maintenance of resting pressures. The internal sphincter is surrounded by an external sphinct...

Forty six patients (median age 61 years; 42 women) with faecal incontinence and 16 age and sex matched controls undergoing a restorative proctocolectomy were assessed by clinical examination, anorectal physiology, and anal endosonography. Forty patients (87%) with faecal incontinence had a sphincter defect demonstrated on anal endosonography (31 external and 21 internal anal sphincter defects)....

The ultrastructural features of the internal anal sphincter (IAS) muscle were studied in biopsies from five patients with neurogenic anorectal incontinence and six control subjects undergoing anorectal excision for cancer, or for inflammatory bowel disease. In the patients with idiopathic neurogenic anorectal incontinence the internal anal sphincter showed loss of smooth muscle cells, disruptio...

Changes of denervation in the anal sphincter striated and smooth muscle in patients with neurogenic faecal incontinence are well established. This study aimed to determine if there is also a more proximal visceral autonomic abnormality. Thirty women with purely neurogenic faecal incontinence (prolonged pudendal nerve latencies and an intact sphincter ring) and 12 patients with neuropathic chang...

Internal anal sphincter activity has been studied in 84 patients with haemorrhoids and 40 asymptomatic subjects. Activity was estimated by measuring maximum resting anal pressure with a water filled anal balloon probe 7 mm in diameter connected to a strain gauge pressure transducer. There was greater activity of the internal sphincter in patients with haemorrhoids than in controls, but there wa...

OBJECTIVES The aim of this study was to correlate clinical findings of anal sphincter defects and function with a sonographic diagnosis of significant sphincter defects. METHODS This is an observational cross-sectional study on women seen 6 to 10 weeks after primary repair of obstetric anal sphincter injuries (OASIs). All patients underwent a standardized interview including the St Mark incon...