Intolerance mums advice please! (15mo)

[Mummio92]

Hello,

I’m hoping to get some thoughts from parents whose children have had intolerances about whether this could be the cause of my LO’s symptoms.

He’s 15 months and goes through phases of having a couple of weeks of loose poos with lots of wind and then will go back to normal poos.
Alongside this, he also has periods where he doesn’t want to eat much at all and then will return to eating well again.
He’s very small for his age in height (below 9th % despite avg height parents) but weight is ok (25th% and has always been).
A past blood test for an unrelated issue revealed low iron and he has since had supplements though no follow up to see if levels have improved.
He’s largely a happy chappy but noticeably more fussy in the times his tummy is upset. Possibly somewhat more sleepy than usual in these phases too.

On the occasions his tummy is bad I think he’s maybe eating more bread/cereal type foods but I can’t definitively say I’ve noticed a pattern.
He’s also always teething when these symptoms show up most.

So, is it possible for intolerance symptoms (or something like Coeliac’s) to present in bouts, with periods of being fine in between? Or is that unlikely?
Could it just be teething?
Has anyone experienced similar?
And finally, where does one go to have such things investigated?

Thanks in advance!

Keep a food and symptoms diary. Might make it clearer as to what's causing an issue.
Make contact with GP for advice too.
We very much did trial and error with any dietary issues with little ones!

My daughter has many delayed food allergies/food intolerances (both terms get used interchangeably). She has also had toddler diarrhoea and got loose stools due to teething, colds and stress. The night before we moved house she had 9 poos on 2h!

Food diaries were our best friends. It can be 3 days between symptoms and eating a food. When she got the toddler diarrhoea diagnosis I had been tearing my hair out as there was no obvious triggers. The things that helped her medical team suggest toddler diarrhoea rather than another allergy was that she started having poos in the morning before getting up and there was undigested food in it. She had stool samples at the same time which didn't show signs of malnutrition and only mild markers of inflammation. She has had blood tests for coeliacs disease which was negative.
Her appetite comes and goes. Some weeks she eats everything and asks for more and other times she will have one meal over a weekend
She's short too, on the 1st percentile for height and 25th for weight.

Thanks for the suggestion of food diary, sounds like that’s the best next step.

@Superscientist Really appreciate your detailed reply.
I have read about toddler diarrhoea- did your daughter have diarrhoea for every stool when she had this or did it come and go? My son has undigested food in his stools too and primarily only first thing in the morning.
Is it something that passes on its own or did you make dietary changes to help?

She had 1-4 poos a day from between moderately loose and horrendous!

There are dietary changes that can help and they can outgrow it. High fat and low fibre diets can help and avoiding dried fruits and grapes etc. there's advice on the NHS page.

My daughter was bad for about a year and since then she has 1 poo a day that goes from normal to moderately loose so has mostly out grown it. It probably started around 2 and since 3-3.5 it has been a lot better.