I get what sounds like that exact burning sensation sometimes, but not always, when I do the sea-salt cleanse which is just two teaspoons of sea-salt in 4 cups of water. My idea was that it happens only when I've gone lots of times and not to sound gross, but if I'd gone so many times that I've had to wipe that area so many times that it becomes raw. On the times I've done more sea-salt cleanses in a row and haven't eliminated as much, it never happens.