What Causes Passing Of Stool After Every Feed?

hi, my name is Himanshu. my 3 month baby has been passing stools almost after every feed. though the consistency of stools is not the matter of tension but the frequency is somewhat making all including baby irritable. our doc suggested to get a stool culture test done. the brief of her report is like : ph - 6.0, reducing substance - negative, form and consistency - semi digested, reaction - acidic, pus cells - 0.3/hpf and apart from this a long list of various items having resistant, sensitive as result, I hope there is nothing to worry about. thanks,