grzbear
This side effect is generally temporary, however, dependent upon case, may last from a day or two to several months...
You can try and change the strains you are using and see if that helps. Some strains may be gentler on you than others.
What the probiotics are doing is digesting and cleaning out the waste in your digestive tract and this causes the discomfort. If you have had bowel disorders such as colitis, IBS, etc. you may be in for a long haul to correct things...
To tell you the truth... If you did not experience this, I would wonder if the product was working.
Prescriptions for over a trillion organisms a day for 1 - 3 months in these cases are not unheard of.
So... how much waste you have in your system, and\or your intestinal condition, will determine the length of time this goes on.
grz-