Fill a large pot with enough water to cover all of the ingredients. Add the crab boil and bring to a boil. Adjust the crab boil to suit your taste. When the water boils, add the potatoes and sausage. Cook on medium heat for 20 minutes. Add corn and cook for an additional 10 minutes. Add shrimp and cook for no more than 3 minutes. Drain and serve with warm bread.