I moved this to general discussion where more people would see it.
First off, what are you doing to slow your gut and thicken stool? That is key to the butt burn issue. As you are finding out, butt burn is better prevented than treated.
But, you can use a barrier ointment religiously, and make sure to combine it with an antifungal cream, as it is common to get a yeast infection from the moisture and warmth. Immoisum can be a good choice to help control the frequency and nighttime leakage, as it improves rectal sphincter tone, along with slowing the gut and increasing water absorbtion. Try eating something fatty at bedtime, as it stimulates the "ileal brake," which is a physaiological slowing of digestion when a fatty snack is sensed in the stomach. Not ice cream, because many are sensitive to lactose early on, but a piece of aged cheese or high fat crackers.
During the day, avoid foods that increase gas and output, and be sure to drink plenty of non-sweet fluids, but not at meal time.
I'm sure others will have some good tips for you.
Jan