You can use honey in place of sugar. Place the frog in a luke warm bath of de-chlirinated water that has 4 to 5 drops of honey dissolved in it. The bath should be no deeper than up to the frogs chin.

Now this bath is also used to treat impaction so watch carefully and keep the frog in the bath until the swelling reduces in the prolapse. You can use a cotton swab to gently replace the prolapse back in. Get a vet appointment ASAP to make sure the frog is ok even if you get the prolapse back in.