Place kidney beans and 5 cups water in a programmable pressure multicooker (such as Instant Pot). Cover cooker with lid, and lock in place. Turn steam release handle to SEALING position. Select PRESSURE COOK setting. Select HIGH pressure for 15 minutes (it will take about 8 to 10 minutes for cooker to come up to pressure before cooking begins). Carefully turn steam release handle to VENTING position, and let steam fully escape (float valve will drop). This will take about 2 minutes. Remove lid from cooker.

While beans cook, heat oil in a large, heavy pot over medium. Add sausage; cook, stirring often, until evenly browned, about 10 minutes. Remove sausage from pot, and drain on paper towels.

Add onions to pot, and cook over medium, stirring often and scraping up any browned bits, until well browned, about 8 minutes. Add celery, bell pepper, Creole seasoning, black pepper, garlic, bay leaves, and sage. Rub the basil between the palms of your hands, and add it to the pot. Cook, stirring occasionally, until vegetables are very soft, about 10 minutes. Stir in sausage, and remove from heat.

Add half of cooked beans to pot; mash with a potato masher until mixture is creamy. Stir in remaining beans and cooking liquid until it has the consistency of gravy.

Stir in scallions, parsley, and hot sauce. Serve with rice; garnish with parsley and hot sauce.