Constipation in 4 month old

[Hofknocker]

Hi everyone this is my first post.
My 4 mth old girl can go up to 2 weeks without pooing. She seems generally healthy and happy. We've tried soap up the bum, sugar water, puréed prune and the medicine Lactulose. The medicine worked after 4 days but is hard to administer.
Health visitor has no more suggestions. Doctor suggested lactose intolerance but she has no symptoms.
Please help.

Breast fed or formula fed?

Mixed feeding at the beginning but now totally breast feeding to try and solve this issue.

It's not clear from your post what the problem is with the infrequent poos - does she seem to be in pain? Long gaps between poos can be normal in an EBF baby, I wouldn't go giving prunes to a pre 6 month old unless strongly medically advised to.

It is quite normal for breast fed babies to go a long time without pooing (my DD1 made it to 21 days once). I don't know whether mix-fed babies also slow down.
Other more knowledgeable posters may be along soon but personally I think if she is healthy and happy I probably wouldn't be trying to fix this. Maybe it's just how she works. Surely if she had a problem with an intolerance it would show up in other ways (e.g. Crying a lot, signs of discomfort )?

The doctor has advised that it isn't good for a baby of this age to go this long without pooing. She also sleeps much better for the few days after she has pooed.

soap up the bum

Is this not just an old wives tale? I would imagine lactulose is easier to administer?!