Are you following the forums diet or the website. On the forum diet you can introduce kefir after two weeks I believe, your body may not be ready to handle it right after a cleanse. You should stick to making your own kefir. I ve used commerical kefir before without a problem but the one you bought may not have been fermented completely to reduce the lactose comtent which feeds candida.
Bloating is expected try to eat smaller portions. I experienced bloating early on also well.