Anorectal abscess and fistula are intimately connected in anatomy, etiology, and morbidity. They have been extensively described, but only sparingly studied in randomized controlled trials. These trials, covering such issues as primary suture of abscess, whether or not to perform a fistulotomy at the time of abscess drainage, and comparison of fistulotomy and fistulectomy, are the focus of this article. Important gaps in our knowledge and subjects for new trials are also discussed.