In a small bowl, whisk together the BBQ sauce (or ketchup), soy sauce, garlic, and sweet chili sauce. Set aside.
Heat the oil in a pan or wok over medium-high heat. Add the onion and peppers and cook, stirring frequently, until the onion becomes translucent, about 5 minutes.
Add the sausage and cook for 8-10 minutes, stirring occasionally, until browned.
Pour in the sauce and stir frequently until it thickens and coats the sausage and vegetables, about 1 minute.
Remove from heat, add salt and pepper to taste, and serve over white rice.