A study published in Gut has shown that certain genetic polymorphisms are associated with adverse pouch outcomes after ileal pouch–anal anastomosis in patients with ulcerative colitis. Genetic and clinical information was available for 714 individuals. The NOD2insC risk allele was significantly associated with chronic pouchitis and a Crohn's disease-like phenotype after surgery. Other polymorphisms were also found to be associated with pouch outcome, although with slightly weaker effects.