Goat milk??? TMI

so, my 15 month old has struggled with digestion since birth. before 12 months he'd spit up 6 times an hour. now, he keeps it down, but struggles to poo every day. grunts, cries, bleeds, huge poos. We've tried all the prunes, juices, miralax, suppositories in the world, but the poops would be so hard he'd hate to go and hold it. After a day of goats milk, he passed a perfectly appropriate sized, soft firmed stool with no crying..... has anyone else tried this remedy???