Treatment of non-IBD anal fistula.

The course of the fistula tract in relation to the anal sphincter is identified by clinical examination under general anaesthesia using a fistula probe and injection of fluid into the external fistula opening. In the event of a complex fistula or in the case of fistula recurrence, this should be supplemented with an endoluminal ultrasound scan and/or an MRI scan. St. Mark's fistula chart should be used for the description. Simple fistulas are amenable to fistulotomy, whereas treatment of complex fistulas requires special expertise and management of all available treatment modalities to tailor the right operation to the individual patient. The given levels of evidence and grades of recommendations are according to the Oxford Centre for Evidence-based Medicine (www.cemb.net).