We don't use it. I was told that its a pretty outdated type of enzyme. It is not enterically coated, so it starts to work in the mouth (like Amysmom says -- thus the burning). The beads hold together until the gut and work there where you need it. Viokase powder is a good choice for tube feeds though, especially through the night, because you can mix it right into the formula so that they get some throughout the whole night.
I hope this helps.