A 31-Year-Old Patient With Colitis and Perianal Disease

Abstract

31-year-old man with a 1-year history of Crohn’s disease (CD) returns for evaluation of new perianal pain and drainage. Four weeks ago he developed worsening pain with sitting down and with bowel movements. Last week he developed purulent perianal drainage that stains his undergarments. He now has 5 bloody bowel movements per day with associated urgency. He has lost 5 lb during the past month. Colonoscopy at diagnosis 1 year ago revealed a normal terminal ileum, moderate right-sided colitis, and proctitis. Remission was induced with steroids and maintained, until now, with azathioprine (AZA). On physical examination, his abdomen is soft with mild tenderness in the left lower quadrant. Examination of his perineum reveals a tender draining perianal lesion at 7 o’clock with surrounding induration that produces purulent fluid with modest pressure. On digital examination of the rectum there is no fluctuance or masses, but he is tender in the 7 o’clock region. He complains that his symptoms interfere with work because it is difficult to sit at his desk for long periods of time. He believes he could handle the other CD symptoms, but his perianal symptoms are much more upsetting and disruptive. The Problem Perianal disease is a debilitating and common manifestation of CD. In a US population-based study, perianal fistulas occurred in 21% of patients by 10 years after diagnosis and in 26% of patients by 20 years after diagnosis. Patients with CD and perianal involvement are more likely to have a disabling or relapsing disease course and are at greater risk for colonic resection. Before biologic therapy, 23% of patients with perianal CD underwent proctocolectomy or proctectomy and permanent ostomy. Symptoms of perianal drainage and pain, a relapsing disease course, the need for multiple surgical procedures, and, in some cases, incontinence from aggressive surgical interventions all can lead to significantly decreased quality of life in patients with perianal CD. Optimal evaluation and management of perianal CD begins with an understanding of the anatomy of the anal canal, which is formed by the internal and external anal sphincters. The internal anal sphincter is composed of smooth muscle and is not under voluntary control. The external anal sphincter is formed from skeletal muscle arising from the puborectalis and