An ostomy device that comprises an adhesive wafer for attaching to the skin around the stoma. The wafer comprises an adhesive layer having a proximal adhesive side and a distal side, where the distal side is covered with a backing layer. The wafer comprises a central portion and a peripheral portion, and it comprises a proximal section located on the proximal side of the central portion and a distal section visually arranged on the distal side of peripheral portion, wherein the distal section changes colour when the proximal section is exposed to fluid.