Respray skillet with cooking spray. Add bell pepper; cook 2 minutes over medium-high heat, stirring frequently. Add sausage; cook 2 minutes until lightly browned. Add garlic and cooked shrimp. Cook 1 minute, stirring constantly. Add 1/4 cup water; cook 30 seconds, stirring to loosen brown particles. Remove from heat; cover. In 2-quart saucepan, heat 1 1/2 cups water to boiling. Gradually stir in grits; reduce heat. Cover; simmer 5 minutes. Stir in milk. Remove from heat. Add remaining ingredients. Serve grits with shrimp mixture.