Absolutely! For about 2 weeks take two caps of a good probiotic on an empty stomach first thing. I like to do a probiotic implant enema. You add the 2 caps to a quart of warm water, inject it and retain it as long as possible, massaging to get it to move through the entire colon then expel.
Fiber is a great idea. Be sure to get a good blend of soluble/insoluble (like flax and psyllium). Be SURE to drink ample water when taking fiber to avoid clogging!!
Another great addition to your program is enzymes. Take 2 first thing, about 20 minutes apart from your probiotic, then 2 with every meal and 2 at bedtime for a total of 10 a day for two weeks after your fast to really help things along. Look up enzymes if you have any questions--lots of info available.