Sorry to hear about your frog. There is a treatment you can try that may fix the prolapse. You can use either method:

Method 1: place frog in a sterile tank, add 1/2 teaspoon of sugar to 1/2 cup of spring water at room temperature and mix well. The frog should remain undisturbed for 2 hours.

Method 2: instead of sugar water, use Pedialite and follow above instructions.

This really works, however in case it doesn't, the frog needs to see a vet ASAP.