Baby unable to pass poop

Hi, my lo is 6 weeks old and she cannot pass poop on her own since she turned 4 weeks. She is ebf and her poops are pasty mustard so I dont think she is constipated. It seems like she doesnt know how to push the gooey stuff out of her rectum. I have tried qtip and that always initiates a BM but my doc suggested not to make a habit of it since that could meddle with her rectal muscles development. I have tried massaging, bicycle kicks, warm baths, prune juice, colic drops.. pretty much everything but nothing seems to work. Last time she had a bowel movement was 3 days ago when i massaged her rectal opening (sorry TMI) during a diaper change. The sad part is she is in a lot of pain due to that and i dont want to make her reliant on qtips/suppositories or any other form of assisted stimulation. Would appreciate any help on this.

Thanks!