The main object of the present invention is to provide an agent for the treatment of inflammatory bowel diseases.The present invention relates to an agent for the treatment of inflammatory bowel diseases containing the heterocyclic derivative represented by the following general formula (1) or a pharmaceutically acceptable salt thereof as an active ingredientIn the formula (1),and are the same or different and each represents an optionally substituted arylR3 and R4 are the same or different and each represents hydrogen atom or alkylR5 represents hydrogen atom, alkyl or halogen atomY represents N or N→OA represents NR6, and R6 represents hydrogen atom, alkyl, etc.D represents alkylene or alkenylene which is optionally substituted with hydroxyE represents phenylene or a single bondG represents O, S, etc. andQ represents carboxy, alkoxycarbonyl, etc.
