so either you did not clean up your diet for long before The Master Cleanse or you are not drinking enough water during the cleanse to aid you body in elimination of the toxins. it is also suggested that you bath 2 time a day while cleansing. you skin is an elimination organ too. a detox bath to help you:
1 cup Sea Salt + hot bath for 30 minutes
scrub off and rinse.
watch you may be dizzy from the hot bath.