Add the sausage, chicken, onion, red bell pepper, green bell pepper, celery, garlic and diced tomatoes to a large slow cooker.
Pour the chicken broth into the slow cooker, then add the buffalo sauce, Old Bay seasoning, parsley, oregano, thyme, cayenne pepper, red pepper flakes, salt and black pepper.
Mix everything together and cook on high for 3-4 hours or on low for 6-8 hours.
About 30 minutes before serving, cook the rice according to package directions, and add to the slow cooker.