GP and pharmacist giving conflicting advice

[Element4056]

Since giving birth nearly 3 weeks ago I have been constipated. When I first spoke to mu GP she prescribed me senna as a laxative. I queried whether this is safe for breastfeeding as my baby was less than 2 weeks old. She said it's fine to take whilst breastfeeding.
I sent my husband to the pharmacy and he double checked with the pharmacist who stated this is unsafe for breastfeeding a baby less than a month old.
Instead the pharmacist recommended fybogel. As I was still constipated I also bought lactulose which helped with bowel movements the first time.
I have now been constipated again for nearly 10 days and taking lactulose and fybogel hasn't helped like the first time. I called my GP today and she prescribed movicol. Again i reiterated that my baby is less than 3 weeks and breastfeeding. She said it was fine to take.
I sent my husband to the pharmacy and the pharmacist recognised him from before. The pharmacist called over another pharmacist colleague of his and they both stated that movicol cannot be taken whilst breastfeeding a newborn at less than 3 weeks old. I am so baffled. Why would my GP prescribe these laxatives if they are unsafe to take whilst breastfeeding?
The pharmacist recommended I take laxido instead which my husband purchased.
I'm annoyed as I am entitled to free prescriptions and instead have had to buy lactulose, fybogel and now laxido due to my GP prescribing medication I cannot take.
Can someone in the medical field with knowledge please advise if movicol is indeed unsafe to take whilst breastfeeding my less than 3 week old? I'm frustrated that I am getting conflicting advice from both the GP and pharmacist.
Thank you for reading.

Macrogol is safest -- laxido, movicol etc. I don't see how these would end up in breast milk at all, it is a high molecular weight osmotic that can't pass out of the gut.

Lactose is also fine, it's similar but it's a sugar that isn't absorbed.

I'd avoid senna and things that work by causing the bowel to spasm except as a last resort.

You do need to drink a lot of fluid while breastfeeding in the early months, up to 3l a day is not unusual. If your urine is darker than 'light straw' try drinking more.

Get to a big supermarket tomorrow and stock up on tinned prunes and prune juice. I have chronic constipation and drink a glass of prune juice every day to help.

Also drink a lot of water. I drink pints of warm water (2/3rds cold, 1/3rd boiling) when I haven’t been for a day or so, and that helps get things moving.

I would always go with what the pharmacist says, they are much more knowledgeable about medication than GPs.

They obviously weren't more knowledgeable if they sold the same product to OP that was on the prescription but that they had to pay for

As pp said, the drugs in breastmilk helpline is brilliant. If the information you need is not in their factsheet, you can email them and their specialist pharmacist will get back to you.

I was discharged from hospital with a box of movicol when dd was a few days old (and have taken it long term whilst breastfeeding dd).

Thank you so much everyone for your advice. I will be sending DH back to the pharmacy tomorrow to see if I can get the movicol prescription and ask for a refund for the one purchased.
I will also be telephoning my GP surgery to change over and have a different pharmacy designated for electronic prescriptions to be sent to.
Thanks again for the reassurances. My own research prior to sending DH over to the pharmacy indicated that they we're essentially the same drug which is why I was so confused when they refused to dispense it.