I don't know what long time use of H202 would do to one's digestion, but I can say with great enthusiasm that hydrogen peroxide can be used in a very therapeutic bath.
Fill bathtub with very warm water...or hot as you can stand.
Add 1 to 3 cups of Epsom Salts
Then add hydrogen peroxide (H2O2) - 1 pint to 3-4 quart of 3% solution.
Depending on your illness or weakness, you may need to only stay in this water for a short amount of time. 10 minutes may be all you can handle. 20 minutes is normal for some and for healthier people 30-60 minutes works for them. The idea is to sweat and detox.
Afterwards always take a cold shower until your body cools down.
This is the way I started everything. Once I realize how well that worked for me, I then tried other things that are part of this protocol.