In a skillet over medium heat, brown the sausage. Once cooked, remove the excess grease by discarding the fat in the skillet and placing the sausage slices on paper towels to absorb any remaining grease. Set aside. In the same skillet, cook and stir the chopped bacon until crispy for about 6 to 8 minutes. Remove the bacon from the skillet and set it aside. Next, add the okra to the hot bacon drippings and cook and stir until tender, which usually takes around 5 minutes. Finally, drain off any excess oil by placing the okra in a colander and discard of any leftover bacon drippings.
In a saucepan over medium heat, combine the okra and diced tomatoes. Bring the mixture to a simmer and then reduce the heat to medium-low. Let it simmer for approximately 10 minutes.
In a large soup pot, melt the butter over medium heat. Add the onion, green onions, green pepper, celery, parsley, and garlic. Cook and stir until the onion starts to brown slightly, about 10 minutes. Remove the cooked vegetables from the pot but leave the butter behind. Stir in the flour while reducing heat to low. Continuously stir the mixture (roux) until it reaches a rich milk chocolate color, which should take around 30 to 45 minutes. Take care not to let the roux burn.
Once the roux has reached its desired color, whisk in 2 cups of water. Increase the heat to medium and add salt, pepper, cayenne pepper, thyme, and bay leaves. Bring the mixture to a boil before stirring in the sausage, bacon, okra-tomato mixture, and an additional 6 cups of water. Reduce heat to medium-low and simmer the gumbo for about 45 minutes or until it thickens and flavors blend together. Finally, add the shrimp and continue simmering until they turn pink and opaque (approximately 6-8 minutes). Remember to remove and discard the bay leaves before serving. Adjust seasonings if necessary according to your preference.