Possible lactose intolerance / side effects

[Snicci]

Hoping someone can give me a bit of advice if they have been in a similar situation.

My LG is 18 weeks on Wed and was breast fed for the first couple of weeks but I had to stop. Put her onto Cow and Gate Stage 1 formula and she has had around 4-5 runny nappies per day which was causing nappy rash. She also dropped down the percentile chart for weight (9th percentile) and was only 11lb15oz at 15.5 weeks (birth weight 7lb4oz - 5 days late).

Going on the advice of the HV last week, I decided to switch her formula to Cow and Gate Infasoy to see if that would make a difference and now she only has around 1 dirty nappy a day and is really quite constipated and visibly straining and her bottom is very red (but not rashy)!

I've tried giving her cooled boiled water which she takes a couple of sips from then just spits it out. I then tried diluted baby juice suitable for babies from 4 months + which again she took a few sips of then spat it out to try and get extra liquids into her system to relieve the constipation but I am failing miserably! :( Ive also been massaging her stomach or moving her legs in a bicycle motion but it doesnt seem to be having any effect.

I really dont want her to have a sore bottom / sore stomach from being constipated, but I also dont want her to have constant explosive, watery, dirty nappies from possibly being intolerant to lactose.

I also need to give her a Gaviscon sachet in her formula to help her reflux. This can also make her a bit more constipated so I really am keen to get fluids into her.

Would it be wrong to give her 2 x bottles of Cow and Gate Stage 1 (lactose milk) which gave her a runny tummy, but didnt appear to hurt her stomach or cause distress as well as giving her 3 or 4 bottles of infasoy (lactose free) formula to hopefully "soften" things slightly...or would the change in formulas cause further problems?

Planning on calling the HV for advise tomorrow but hoped someone may have some advice to help. Thought about adding extra water to her formula but read this could be dangerous so not willing to try that.

All advice welcome - thank you

Have you tried colief? You add a few drops to normal formula - it's an enzyme which breaks down the lactose. Not cheap, but we found it really worked for dd. Temporary lactose intolerance can be a fairly common after effect following a stomach bug. For dd the main giveaway for us that she was lactose intolerant was red raw nappy rash. But was only temporary. We used to use a bottle until it ran out and only buy more if symptoms came back.

Your dr can prescribe you lactulose for the constipation - my ds was on gaviscon which severely constipated him plus changing his formula didn't help. The lactulose definitely worked though.

Have you tried lactose free formula?

Lactose intolerance is actually pretty rare in babies. Having problems with the cows milk proteins found in dairy and formula is far more common.

Soy formula isn't recommended as a main source of nutrition as it carries risks. more NHS info here and it sounds like it's not suiting her either. There are much better hydrolysed formulas available which I would talk to your HV or GP about.