Wow! Basically there are two forms of bloating: hard and soft. The hard is caused by a bacterial infection and is treated with an antibacterial. Generally hard bloats are fatal due to kidney failure.

Your frog has a soft bloat, sometimes referred to as the "Michelin-man" syndrome. The only treatment is immerse the frog in a salt bath. It is caused by an accumulation of fluids in the body due to an osmotic imbalance. These imbalances are generally caused by poor maintenance of the tank or inadequate diet. Feeding freeze-dried foods are a main cause of this type of bloating. Aquatic frogs are known to live in this state for quite sometime - they are without doubt a tough frog. But eventually if the swelling doesn't go down, kidney damage will result and it is 100% fatal. It is a good idea to give the frog to someone that has experience in treating this condition.

As a side note - these frogs are quite salt tolerant and can live in brackish water (40-60% seawater) and water that is highly acidic.