What causes acidic poos?

[Haribosmum]

DS2 has had these really acidic poos for a couple of weeks. He IS lactose intolerent and awaiting some allergy tests at the local childrens hospital. He's not had any dairy for about 4 weeks (we tried him on 'normal' formula to see if he had outgrown his intolerence yet) and yet he's still got these really yucky poos that 'burn' his bum. My MIL had the kids last night and she smothered his bum in Metanium which cleared him up but as soon as he pooed again he started bleeding . I'm starting to think he has an allergy/intolerence to another foodstuff but cannot think what. I just wondered if there could be any other reason he has these acicic poos? He's 100% healthy in all other ways (ie no temperature/sickness etc)

How old is he haribo? My friends ds is lactose intolerant and cant have soya either has a special 'milk' substitute. he couldnt even tolerate breast milk when he was tiny. could it be something simple like slight dehydration that is making him bleed now if his poo is very solid? i do think these things can take a while to identify.

My ds eats a lot of fruit and that can make his bum very sore sometimes. How old is he?

ds has just had a bout of nappy rash where the poo seemed to burn his bum. I also wondered about fruit especially kiwi so stopped it and his bum has cleared. Banana seems OK though. Or maybe the fruit is a red herring and it's teething . He's 7 months.

He's 11 month (today actually ). Maybe I should clarify - his bum is bleeding from sores on his buttocks rather than from his anus. He doesn't have soya milk, he has 'lactose free' milk. The only fruit he really eats is apple and banana so I don't think it's that...

Sounds like teething nappies to me - ds used to react immediately after doing one and would be red raw and sometimes looked like he'd grazed his bum and it would bleed. Is he teething atm? These nappies also usually have a different kind of smell. I always could tell from the smell of ds's nappies that he was teething, same with my mindees.

Looney - I did wonder about teething actually. Poor mite only has 2 teeth and no sigm of any others ATM but I know the move around in the gums before they make their grand appearance....