FL, DS's poo was pretty runny, on his combination of 50% formula and 50% BM. Now that he's on solids as well, but taking less formula, it's more peanut butter-like. colour now depends on what he's been eating - we can even identify pumpkin and zucchini in his nappy. I have been consistently advised that there is no 'normal' for babies poo, and anywhere from runny to paste-like is fine - you just don't want pellets. No-one can tell me what's usual in a BF/FF combination baby either, because most people do one or the other, but as a rule BF babies have runnier poo and FF babies tend more towards the solid poo.

Did you see any other signs which suggest lactose intolerance? I would go back to the original formula for a week or two and see if there is any difference, but if poo colour and consistency is the only sign, I wouldn't worry at all.