How long does baby stool frequency associated with hirschsprung disease last?

Depends. It would depend on timing of definitive corrective surgery, antibiotic usage and resumption of normal diet.
Not sure . Babies with hirschsprung's disease may not be able to have a bowel movement at all. Some may just be constipated or only stool with stimulation of the rectum and anus. There is no fixed frequency of bowel movement.