Abnormal appearance of the internal anal sphincter at ultrasound: a specific feature of progressive systemic sclerosis?

Endosonography is now an effective tool for the assessment of anorectal pathologies. We present a case of rectal prolapse in a patient with progressive systemic sclerosis, with low resting anal pressure, no rectoanal inhibitory reflex in manometry, and a thin, heterogeneous, difficult to delineate, internal sphincter on endoanal ultrasound. We also provide a review of the literature on anorectal involvement in progressive systemic sclerosis.