I too was worried about starting a program, not knowing how my body would react, would I find myself out in public and have to suddenly race to the bathroom... please understand, I HATE using public toilets, especially if I have do #2. The good thing is I have been on this Colon Cleanse for 3 weeks, nearly 4 weeks now, and I have not had any trouble with embarrasing, sudden urges. I did start my program on a day when I worked, but would have 2 days off in a row after that, I figured that the first day wouldn't do much, so I felt safe starting on a workday, but knowing that I had 2 days off after that was a mental buffer for me even though it turned out that I didn't really need it. I didn't start seeing results for nearly a week, and when it started happening, it was fairly gentle, and so far, I have always been able to get home, or get to a "non-public" toilet (usually a relative, or friend's house).
I suspect it depends on what program you are going to use, I went from having a bm once a week at best, to going 3-4 times a day, and so far it hasn't been a problem for me, it started gradually and I have been able to incorporate it into my day.
Do you have an idea of what program you want to try? I do a Colon Cleanse called 4 Total Cleanse (Genesis Today brand), it's a 2 part product, one is to jumpstart your bms, and the other is to detox your body, I also do the P&B shakes, I have elimated the MP ropes, and I do feel much better, cleaned out, lighter, healthier.
I would like to try a parasite cleanse next, I will probably try zapping as well as some sort of internal herb or product, not sure what I will take yet. I will probably start that the same way I started the colon cleanse, on a workday with 2 days off following.