Anal Sphincters Evaluation by Endoanal Ultrasound in Obstructed Defecation

To evaluate anal sphincter abnormalities detected by endoanal ultrasound in obstructed defecation due to rectocele and rectal intussusception.

The retrospective analysis includes 45 patients with obstructed defecation syndrome due to rectocele and/or rectal intussusception with or without fecal incontinence, and submitted to endoanal ultrasound.

Ninety-three percent (n = 42) were women (mean age of 63 ± 12 years), and 47% (n = 21) of the patients had fecal incontinence. In total, 29% (n = 13) had a previous anorectal surgery, and 93% (n = 39) of the women had a previous vaginal delivery. An isolated rectal intussusception was diagnosed in 20% (n = 9) of the patients, an isolated rectocele in 24% (n = 11), and rectal intussusception and rectocele in 56% (n = 25). Thirty-six percent of patients had anal sphincter lacerations (n = 16): 12% (n = 2) had only internal laceration, 69% (n = 11) had only external laceration, and 19% (n = 3) had both. Two patients had a thinner internal anal sphincter with 0.9 and 1.2 mm, respectively. In total, 25% of the patients without fecal incontinence had an occult anal sphincter laceration, and all were women with an external sphincter laceration in the anterior quadrant and a previous vaginal delivery. In patients with obstructed defecation and fecal incontinence, 48% had sphincter lacerations. Previous anorectal surgery was a predictor of anal sphincter laceration (odds ratio [OR] 4.8; 95% confidence interval [CI] = 1.214-18.971; P = .025), but fecal incontinence (OR 2.7; 95% CI = 0.774-9.613; P = .119) and previous vaginal delivery (OR 1.250; 95% CI = 0.104-15.011; P = .860) were not.

Endoanal ultrasound should be considered in obstructed defecation with or without fecal incontinence, especially if surgical correction is planned.