Drain the pineapple, but reserve ⅔cup of the juice, and set the pineapple aside.
In a small bowl, mix the water, vinegar, brown sugar, cornstarch, Worcestershire sauce, salt, soy sauce, and the reserved pineapple juice until smooth. Set aside.
Sprinkle the pork with paprika. In a large skillet coated with cooking spray. Brown the pork in the oil.
Stir the cornstarch mixture, and add it to the pan. Bring to a boil, cook and stir for about 1 minute or until thickened.
Add onion, green pepper, and pineapple. Reduce the heat and simmer covered for about 6 to 8 minutes or until the pork is tender. Serve with rice.