@jsp68 - Welcome to Mayo Clinic Connect!
I can’t imagine how you feel having constipation since birth and not get any long term relief!
Do you know if you had tests done when you were young?
On rare occasions a baby can be born with faulty nervous system in the large intestine. These children start having constipation problems in early infancy.
I’m not surprised that you can’t get fully cleaned out for a colonoscopy. Same here- have very slow motility.
Have they been able to get biopsies when you had colonoscopies?
I hope the new gastroenterologist can help you. Something has to be done if you go weeks without a bowel moment.
Can you post after your visit?
There are many members here with severe constipation that can offer suggestions for you to try.