Add beef sausage, red bell pepper, green bell pepper, yellow bell pepper, white onion, celery, garlic, tomato sauce, diced tomatoes, beef broth, and Cajun seasoning to the crockpot.
Stir well to combine all ingredients. Cover and cook on LOW for 6 to 8 hours or HIGH for 3 to 4 hours.
About 30 minutes before serving, open the lid and stir in the uncooked white rice and shrimp.
Cover and cook for the remaining 30 minutes, or until the rice is tender and the shrimp is pink and cooked through.
Garnish with chopped fresh parsley before serving hot.