A two piece ostomy appliance having a first part (bodyside part) adapted for securing to the body of a user, and second part (pouch part) that is releaseably secured to the first part. The pouch part has a pouch flange which has an opening communicating with an interior of the pouch; and a bodyside flange with an opening and a hydrocolloid layer for securing the bodyside flange to the stoma of a user. The bodyside flange has a location projection receivable in a recess in a part of the pouch flange to align the opening of the pouch flange with the opening of the bodyside flange. A surface of the pouch flange has an adhesive to adhere the pouch flange to the bodyside flange. The recess of the pouch flange is located at the periphery of the pouch flange, extending away from the opening in the pouch flange.