The water suggestion sounds like something worth trying and I would start with it because it is the cheapest option.
I had the same problem after my flushes that I didn't have a bowel movement in the following days. I used bacteria/probiotics to get regularly within a day after the flush and that worked very well. I took the probiotics for 3-4 days. I used Trinity in the past (http://natren.com/pages/htrinmain.html) and it worked well. Next time I am going to use the blood type specific formula from Dadamo and see how this works.
Efficient microorganisms (www.scdworld.com) are also a great tool for any intestinal problems and are very cost efficient. You'll find plenty of info about them on http://www.eminfo.info
You can also use the formulas from Dr. Schulze or Dr. Christopher but for my body probiotics feel much more natural and helpful than herbal laxatives/fiber formulas.