Depending upon how often one is currently having a bm, it may only take a few days to ensure the 2 (preferably 3) daily bms you should have BEFORE starting the IF#2. After you've determined how much IF#1 you need (if you need it), THEN you add the IF#2, and you will likely not experience "urgency" at all after a day or two on the IF#2. The most important thing is to NOT allow yourself to get clogged...make sure you take enough IF#1 and drink PLENTY of water. And don't be surprised if you have a bit of cramping, bloating or "backfiring" :)
There's a lot of folks that are using (or have used) IF#1 & IF#2 for cleansing on my forum here (dedicated to the works of Schulze/Gerson/Christopher): //www.curezone.org/forums/f.asp?f=970
So if you ever wanna stop by and check it out (since the Schulze Forum is so slow these days), please make yourself welcome!