Ostomy paste helps protect the delicate stomal skin from caustic output. Ostomy paste has a caulk-like consistency and often comes in a tube.
The caulk like paste is used to fill in uneven skin contours to help create a flatter surface. A flatter surface is important because the ostomy wafer will adhere better if it is completely flush against your abdomen.
Ostomy paste, like many is meant to increase the wear time of your ostomy system while protecting your skin from the stoma output.