The "Ultimate Fast" uses The Master Cleanse as a base, but adds in a few more things to move the bowels. It doesn't sound like the laxative tea has been enough in your case. Can you extend your fast a day or two? I bet using the psyllium husks will make it worth your while, if you have a little will power left.
This is basically what I have in mind for you to read on that webpage:
"Four times during the day (five if you weigh more than 150 pounds), at three-hour intervals, add 1 tablespoon of Bentonite (Dr. Irons Vit-ra-tox Bentonite, Bentonite Minerals, or equivalent) and 1 rounded teaspoon of psyllium (Dr. Irons Vit-ra-tox Colon Cleanse or equivalent) to about 6 ounces of lemonade. It doesn't matter what time you start adding them, as long as you begin early enough to work in all your doses. These two substances will cleanse your colon. Indeed, most colonics professionals consider Bentonite the only proven method of stripping plaque from colon walls. Shake the mixture thoroughly, then drink it immediately, before it gels."
You can get the Bentonite in a big bottle at your health food store for $10 or less, and a big bag of bulk Psyllium husks for $8 or less. Go for it. They taste fine and don't cause any discomfort, and I'll bet they'll get you to move.
Also, do consider a colonic now and after you're finished your cleanse. I had one for the first time after I did the Master Cleanse, and it was well worth it to know that everything was clean as a whistle in there. I imagined it to be much more embarassing than it actually was... it's surprisingly comfortable.