My son 4.5yrs has very smelly poo, when you walk in bathroom after him it stinks, and smells slightly odd- not that poo usually smells delightful but I'd say it's smells different. Also the poo is very pale beige colour... He's perfectly well in himself, tall and slim, not super skinny. He was lactose intolerant until he was two, wonder if it's anything to do with this?