I really don't know about this. I have had intense pain when trying to do the Master Cleanse, but, I can eat whole oranges everyday without a problem. It might not be the citrus at all, my Naturopath says that any simple sugar will create inflammatory responses, so it may be the Maple syrup. He says that whole fruits are fine because the fiber slows down the absorption of the sugars, but juices and simple carbs like white bread, sodas, and candies create inflammation. I don't know if this is the answer, but it makes sense. I can tell you that I am craving all kinds of bad things right now, all sweet, fatty, and salty.
Perhaps you can either do a raw cleanse or use non-sweet fruits and veggie juices if you want to fast.