Figure 2From: Influence of rectal prolapse on the asymmetry of the anal sphincter in patients with anal incontinenceEndo-anal ultrasonographic view of the anal sphincter in a patient with rectal prolapse: black arrows indicate a submucosal thickening in the anterior right and left quadrants of the internal anal sphincter (IAS: internal anal sphincter; EAS: external anal sphincter; A: anterior; P: posterior).Back to article page