You are so right about having to determine the right amount of psyllium. Some people that have slow transit times have to start out with just a little psyllium or it will gum up the works big time. Most of us can gradually increase the amount we take as we get cleaned out, then depending on the fiber content of our individual diets either cut out the psyllium all together or just take a maintanence dose to keep fiber in the system. Another issue is water, anyone on psyllium has to drink plenty of water and avoid dehydrating liqids.
Used correctly psyllium is great, used in the wrong way it can cause a lot of trouble.