Ok, I've recently been having poops that have resulted in my anus burning....almost as if it were covered in my stomach acid, thats how bad it is.
I had 4 poops in one evening, and they were all very watery and non-solid.
The last one I had was non-solid, tarry and in chunks.
Have you recently eaten any hot (fiery) stuff? Those hot sauces/chilli peppers tend to make your anus burn. Of course, I've had anal burning without it too. Don't remember the cure I used for it. (visual technique, of course).