TRANSRECTAL ULTRASOUND STUDY OF THE PATHOGENESIS OF SOLITARY RECTAL ULCER SYNDROME

Transrectal ultrasonography is of clinical value in anorectal carcinom a and in inflammatory diseases of the anorectum. In this study a rigid linear endorectal probe was used to examine 15 patients with endoscop ically and biopsy proved diagnosis of solitary rectal ulcer syndrome. In 13 of the 15 patients the rectal wall was thicker (mean (SEM) 5.7 ( 0.4) mm; normal values: 2.8 (0.1) mm) near the rectal ulcer. In all th ese cases the muscularis propia layer exceeded the maximum normal diam eter of 2 mm. In nine of the 15 patients the normal rectal wall echost ructure, with five distinct layers, was disturbed and there was fading of the borders between the mucosa and the muscularis propria. Poor re laxation of the puborectalis muscle during straining was seen on ultra sound in 11 patients, as was intussusception of the rectal wall. The o bvious enlargement of the muscularis propria points to a chronic mecha nical load on the rectal wall. The ulcerative lesions are formed in th is area of overloaded rectal wall. The direct visualisation of the pub orectalis muscle during dynamic transrectal ultrasonography indicates that the fact that it does not relax is an important element in the pa thogenesis of solitary rectal ulcer syndrome.