Management of Lateral Anorectal Mass in Crohn's Patient

Diagnosis and Initial Management

The American Gastroenterological Association recommends that medical therapy without surgical drainage is contraindicated in the presence of an anorectal mass that likely represents an abscess or complex fistula in patients with Crohn's disease 1, 2
Examination under anesthesia (EUA) is the gold standard for definitive diagnosis and classification of lateral anorectal masses in patients with Crohn's disease 3
The European Crohn’s and Colitis Organisation suggests that surgical drainage is mandatory before any medical therapy in patients with anorectal abscesses or complex fistulas 1, 2

The American College of Radiology recommends obtaining pelvic MRI with contrast before surgical intervention to define the anatomy of complex fistulas and identify occult abscesses in patients with Crohn's disease 5, 6, 3
MRI is specifically recommended for perianal Crohn's disease with complex fistula or history of failed seton by the European Society of Gastrointestinal and Abdominal Radiology 5, 6

The Society of American Gastrointestinal and Endoscopic Surgeons recommends loose seton placement as the appropriate initial surgical treatment after drainage of any abscess in patients with Crohn's disease 1, 2, 3
The American Society of Colon and Rectal Surgeons suggests that for complex perianal fistulas in Crohn's disease, no surgical therapy other than drainage and loose seton placement should be performed in the acute setting 2

The National Institute for Health and Care Excellence recommends metronidazole 400-500 mg three times daily and/or ciprofloxacin 500 mg twice daily as first-line medical treatment for simple perianal fistulas in patients with Crohn's disease 3
The American Gastroenterological Association suggests that anti-TNF therapy (infliximab) combined with immunomodulators is first-line medical treatment for complex perianal Crohn's fistulas after surgical drainage and seton placement 3

The European Crohn’s and Colitis Organisation recommends proctosigmoidoscopy to assess for concomitant rectosigmoid inflammation in patients with Crohn's disease and perianal fistulas 3
The American College of Gastroenterology suggests that active proctitis is a contraindication to definitive fistula repair and requires medical control first in patients with Crohn's disease 2