Remove sausage meat from casings. In a large heavy skillet heat oil over moderately high heat until hot but not smoking and cook sausage, stirring to break up lumps, until golden. Transfer sausage with a slotted spoon to a plate and pour off all but about 3 tablespoons of fat from skillet. Add bell peppers and garlic to skillet with salt and pepper to taste and cook over moderate heat, stirring, until bell peppers are softened, about 5 minutes.
In a blender or food processor coarsely purée tomatoes with juice and stir into bell pepper mixture with sausage. Simmer sauce, covered, stirring occasionally, 15 minutes. Sauce may be made ahead, cooled completely, uncovered, and chilled, covered, 1 day or frozen 1 month.
In an 8-quart kettle bring 7 quarts of salted water to a boil. Cook orecchiette until al dente (about 6 minutes for fresh, longer for dried) and drain in a colander. In a large heated bowl immediately toss pasta with sauce.