Poop after every feed

Hi there! I would like to ask.. My LO recently poop after every feed (FM) ever since I change her FM to Similac Stage 2.. Her poop looks diarrhea-like.. I did try to change her to Dugro Soy, still the same.. Tried giving her Smecta & LactaFort, also still the same.. Initially, she had no issues when it was in Stage 1.. Active as usual.. Eat some solids like rice, bread, egg tofu, carrot, chicken.. Should I worry? This has been ongoing for 3-4 days, I think.. #help