If it's not teething poos, it sounds like it could be Toddler Diahrroea My youngest has it (and in hindsight DD2 had it as well) and eating too much fruit and any fruit juice at all is a problem. He also can't have food that are too high in fibre so grain bread and muesli bars are out as he will pass them almost undigested.. He will still have a bad day with loads of really runny poos but I can pin point it to what food or drink he has had. It is not considered to be a drama as such - his paed said to just keep an eye on it and most kids will grow out of it.