DS is 3.9 and has a cold. However, for 2 weeks he has had a stomach bug on and off. Diarrhoea for a day or two and then fine for a few days; diarrhoea then starts again. He is fine otherwise and wants to eat and drink normally. I stop his milk on days when he has diarrhoea. Is this just a bug which will clear up? Should I leave off milk for longer? This is hard as he loves his milk.