A novel use of PYY or a PYY agonist is disclosed for treating a bowel condition such as inflammatory bowel disease (e.g. ulcerative colitis and Crohn's disease), bowel atrophy, loss of bowel mucosa and loss of bowel mucosal function. The novel use is based on the discovery and demonstration that administration of PYY or a PYY agonist to an animal can protect the colon from injury induced by a hapten known to induce colitis.