Boil a large pot of salted water over high heat. Add the small shell pasta and cook according to package instructions, about 8–10 minutes, until al dente. Drain and rinse under cold water.

In a large mixing bowl, combine drained whole kernel corn, drained Rotel, and chopped green onions. Stir well.

In a medium bowl, mix mayonnaise and sour cream until smooth and creamy.

Pour the creamy dressing over the corn and vegetables. Stir gently to coat everything evenly.

Fold in the cooled pasta and then sprinkle in the shredded cheddar cheese and mix until well blended.

Cover tightly and chill in the refrigerator for at least 1-2 hours before serving.