Intestinal fistula is a rare complication in necrotizing enterocolitis (NEC) and is typically associated with a colonic stricture. We report the case of a preterm infant with severe NEC, who developed an ileocolic fistula followed by the appearance of a colonic stricture after surgical treatment. This report shows how complex the outcome of NEC can be: a contrast enema should be done in NEC when the clinical or biological outcome is not favorable, in order not to delay the diagnosis of intestinal fistula.