S. Halligan et al., ENDOSONOGRAPHY OF THE ANAL SPHINCTERS IN SOLITARY RECTAL ULCER SYNDROME, International journal of colorectal disease, 10(2), 1995, pp. 79-82
Twenty-one patients with histologically proven solitary rectal ulcer s
yndrome (SRUS) were examined by anal endosonography (AES) in order to
determine the frequency of any ultrasound abnormality. Comparison was
made with a group of 17 age and sex matched asymptomatic subjects. Fou
r patients with SRUS had anal sphincter defects on AES. All were of th
e internal anal sphincter (IAS), which appeared fragmented in two pati
ents with complete rectal prolapse. Measurements of internal and exter
nal anal sphincter (EAS) diameter and cross-sectional area were taken,
excluding the 4 patients with defects. The submucosa was inhomogeneou
s (P = 0.0016) and thickness increased in patients with SRUS (median 4
.0 mm vs 2.0 mm; P<0.0001). IAS diameter was increased (median 3.8 mm
vs 2.0 mm; P<0.0001), as was cross-sectional area (median 241 sq mm vs
112 sq mm; P < 0.0001). EAS diameter was also increased (median 8.5 m
m vs 7.0 mm; P = 0.0173), as was cross-sectional area (median 905 sq m
m vs 594 sq mm; P = 0.0052). The ratio of EAS to IAS thickness was red
uced in patients with SRUS (median 2.6 vs 4.0; P = 0.0029). The mechan
ism of these changes is unclear but apparent muscle hypertrophy on ult
rasound may diagnose those patients with SRUS in whom defecatory diffi
culty is a predominant symptom.