Our guts are all different, and what works for one person, may not for the next, even if one could state, with certainly, that something was effective to begin with.
The VSL#3 formulation has been discontinued but I'm told one can still locate probiotic VSL#3 in Europe, manufactured in Italy. No guarantees on the final different formulation, however. Do some serious research!
https://www.vsl3.com/ibs