My 3 year old grandson has always had unusual poo. It is runny and looks like mud. Smells quite offensive too. His mum says she thinks he is lactose intolerant as cows milk goes straight through him. She has tried him on soy milk but he dosen t seem to cope well with that either. He won t drink goats milk. He also has excema on both cheeks all year round but nowhere else on his body. He looks normal size and healthy but gets lots of colds. I thank you for your advice.