Brown rice should never be eaten on a Candida diet as it’s nothing but pure starch which will turn into sugar upon digestion.
What are the ingredients in the chickpea toast and the wheat-free-sugar-free-gluten-free biscuits? You should also stop eating quinoa. If you want the strict diet which has been tested many times over so that you’ll know what affects the Candida and what doesn’t, just ask. Theirs is no use in testing foods that will cause problems with the Candida if it’s already been done for you.
The diarrhea is probably caused by the die-off toxins since you’re killing at least some of the Candida with the diet you’re on.
You shouldn’t lower your vegetable fiber intake as Thomas suggested unless you know why you’re doing it as this can cause more harm than good on a Candida treatment. This is one of the few ways to keep the beneficial flora in your intestines thriving and multiplying because the fiber serves as their food supply. Without food, they’ll simply die-out and the infestation will continue indefinitely.
Read the protocol linked below if you want to follow the treatment.