In a large Dutch oven heat 2 tablespoon of olive oil. Make th Italian sausage into bite-size meatballs about a 3/4 to 1-inch balls.
Cook meatballs in the Dutch oven until they are no longer pink inside. Time may vary depending on the size of the meatballs. Remove the meatballs from the Dutch oven and set aside. Drain any excess grease.
Add the other tablespoon of olive oil to the Dutch oven and add the green pepper, onion, garlic, carrots, mushrooms, and celery. Cook for 5 to 8 minutes or until the vegetables are just about tender.
Add the diced tomatoes, vegetable broth, parsley, oregano, basil, bay leaf, and pasta. Turn the heat up to medium-high and bring to a boil. Reduce heat to medium and continue to cook until the pasta and the vegetables are tender about 15 to 20 minutes. Season with salt and pepper.