It is very important for you to do a colon cleansing routine every day that you fast. You can get a good herbal laxative tea, and have a strong cup in the evening and again in the morning.
Or, a cup of lax tea in the evening, and do a salt water flush in the morninig. This is effectively an "oral colonic", cleansing your digestive tract from top to bottom, but does take some getting used to! You mix 1 qt. warm purified water with 2 tsp. uniodized Sea Salt , and drink it down in the morning. Within about an hour it will all come out the other end, taking all sorts of debris and toxins along with it (not the thing you want to do if you take the subway to work!). I like to do this no more than twice a week during a fast (I did a 59 day fast this summer, and used the tea, salt water flush and enemas throughout the process.)
You can substitute an enema at any time for the tea or SWF. It is well worth learning to do an enema (there is an excellent page here at curezone, Enemas & colonics with all the info and support) if you are serious about cleansing. An enema can stop a detox crisis in its tracks, which neither the tea nor the swf can do.
Also: Please consider drinking fruit juices in the morning, when your body is naturally in a cleansing mode. Fruits are cleansers. Then, in the afternoon, veggies! This is your rebuilding time, and vegetables do the trick.
You should be drinking 3-6 cups of fresh juices/broth every day, along with lots of extra water!
Let me know if there is anything I can do to help you reach your goal, and enjoy your fast!