Combine the stock or water, bones, onion, green pepper, tripe, butter, and rice in a large saucepan and bring to a boil. Lower the heat and simmer for 2 hours. Add the tomatoes and sugar and cook for 20 minutes more. Pick off any meat on the bones and return to the soup. Add salt to taste. Serve Slow Cooker Method: Combine all the ingredients in a slow cooker. Cover and cook on low for 6 to 8 hours. Pick off any meat from the bones and return to the soup.