I took a high strength 30 billion CFU 30 strain for 2 weeks at the start of April and it has given unbearable progressive symptoms since.
I suggest you read the Ingredients. Just because it is a Probiotic doesn't mean that it has all good ingredients.
You may be sensitive to one or more of them.
I have been taking a 6 strain 260 billion CFU's. After listing the 6 strains, the label makes a point to list all the other negative things that aren't in it.
[Does not contain: Artificial colors, flavors, preserevatives, sugar, gluten, soy, wheat, or FOS]
That doesn't mean that yours does, but suggest that some do include those items in there products.