Well there is a lot of candida developping in long threads and drilling into the intestinal walls so yes, cleansing your intestine and killing them will cause die-off.
You want to stay away from leaky gut. Sooooooooooooo, stop the clease AS SOON AS you get intestinal pain. The protocole with the formula surely says so and it is UTTERLY important. We havevery few pain sensors in the intestines, when you do feel pain there it is really important to react fast.
Die off is otherwise a good sign, if however you feel TOO MUCH di-eoff, simply cut down on the dosage. It is all but a race, letting your metabolisme adjust progressively is also important. Listen to your body!