The risk factors for developing fistulas were low intersphincteric (OR 2.77, 95CI 1.50–5.06) and ischioanal (OR 2.48, 95CI 1.36–4.47) abscesses, Crohn’s disease (OR 5.96, 95CI 2.33–17.2), history of recurrent anal abscesses (OR 4.14, 95CI 2.47–7.01) or repeat surgery (OR 5.96, 95CI 2.33–17.2), E. coli-positive pus cultures (OR 4.06, 1.56–11.4), or preoperative C-reactive protein (CRP) levels of more than 100 mg/L (OR 3.21, 95CI 1.57–6.71) (Table 2). The gene discussed is CRP; the disease is Crohn disease.