Anorectal Physiology in Solitary Ulcer Syndrome: A Case-Matched Series

Abstract

Solitary ulcer syndrome is a rare condition characterized by inflammation and chronic ulcer of the rectal wall in patients suffering from outlet constipation. Despite similar surgical options (rectopexy, anterior resection), solitary ulcer syndrome may differ from overt rectal prolapse with regard to symptoms and pathogenesis. The present work analyzed differences between these conditions in a case-control physiology study. From 1997 to 2002, 931 consecutive subjects were investigated in a single physiology unit for anorectal functional disorders. Standardized questionnaires, anorectal physiology, and evacuation proctography were included in a prospective database. Diagnosis of solitary ulcer syndrome was based on both symptoms and anatomic features in 25 subjects with no overt rectal prolapse (21 females and 4 males; mean age, 37.2 +/- 15.7 years) and no past history of anorectal surgery. They were compared with age-matched and gender-matched subjects: 25 with outlet constipation (also matched on degree of internal procidentia), 25 with overt rectal prolapse without any mucosal change, and 14 with overt rectal prolapse and mucosal changes. Subjects with solitary ulcer syndrome reported symptomatic levels (digitations, pain, incontinence) similar to those of patients with outlet constipation, but they had significantly more constipation and less incontinence than patients with overt rectal prolapse. Compared with each of the three control groups (dyschezia, rectal prolapse without mucosal change, and rectal prolapse with mucosal change), subjects with solitary ulcer syndrome more frequently had an increasing anal pressure at strain (15 vs. 5, 3, and 1, respectively ; P < 0.01) and a paradoxical puborectalis contraction (15 vs. 9, 1, and 1, respectively; P < 0.05). With respect to evacuating proctography, complete rectal emptying was achieved less frequently in this group (5 vs. 12, 23, and 10, respectively; P < 0.05). Compared with patients with overt rectal prolapse, mean resting and squeezing anal pressures were significantly higher in both groups of subjects with solitary ulcer syndrome and with outlet constipation. Prevalence and levels of anatomic disorders (perineal descent, rectocele) did not differ among the four groups except for rectal prolapse grade and prevalence of enterocele (higher in overt rectal prolapse group). Interestingly, and despite matched controls for degree of intussusception, individuals with solitary ulcer syndrome had circular internal procidentia more often compared with those suffering from outlet constipation without mucosal lesions (15 vs. 8, P < 0.05). This case-controlled study quantifies functional anal disorders in patients suffering from solitary ulcer syndrome. Despite no proven etiologic factor, sphincter-obstructed defecation and circular internal procidentia both may play an important part in the pathogenesis and an exclusive surgical approach may not be appropriate in this context.