In a large pot, heat the olive oil over medium heat. Add the chopped onion, garlic, bell pepper, and celery. Sauté for about 5 minutes until the vegetables are softened and fragrant.
Add the shrimp to the pot and cook for 2-3 minutes until they turn pink.
Stir in the corn, seafood stock, Cajun seasoning, salt, and black pepper. Bring the mixture to a boil, then reduce the heat and let it simmer for 15 minutes.
After simmering, use an immersion blender to puree the bisque until smooth. If you prefer a chunkier texture, blend only half of the mixture.
Stir in the heavy cream and lemon juice, and heat through for an additional 5 minutes. Adjust seasoning if necessary.
Serve hot, garnished with fresh parsley.