constipation! help? tmi

so I've been constipated my entire life (I'm a 23 year old female). everything that helps normal people poop does not work for me except ducolax. but I refuse to live off laxatives. anyways I've been to doctor's about my poop size and the fact that I'm always constipated. I've had a colonoscopy. my doctor's don't know why and basically this is just "nornal" for me. but seriously my poops are about 3 inches thick and super long when I do poop. this can't be normal or healthy😑