DS is lactose intolerant - he's shown clear symptoms of it since he was tiny. We've tried him with dairy off and on over the last few years and the outcome is always bad but he's never been properly "tested".
He's now 3 1/2 and he isn't outgrowing it so we're seeing a dietician to check his diet is ok. She also suggested doing a controlled dairy trial - ie giving him a certain amount of milk every day for a few days up to 2 weeks - followed by having his poo and his blood tested. I'm willing to try but I'm worried that after a day or two he'll need to be back in nappies - either that or I'll be doing a LOT of washing! So I'm not really looking forward to it. I've been reading the NHS website and this is the way they test babies. But it also says you can do it by giving a lactose drink followed by a breath test. This sounds much simpler as it's a one-off and I don't know why they didn't suggest doing it this way with DS.
So I'm wondering if anyone has done this and how old they were at the time.
(BTW - I don't want to offend anyone but I'm really not interested in hearing about food intolerance testing that involves testing your hair or running an electronic wand over your fingers or whatever else it is they do)