Does anyone have experience with an implanted morphine pump for chronic pain?

After 13 years of chronic pain, my body cannot handle oral narcotics anymore. I keep getting sick in my gastrointestinal track - poor motility all the way to an ileus with everything in between. Have had total work-up from GI MD. Everything is fine, but it was felt all my issues were due to narcotics. I don't abuse the narcotics - I don't understand why people like to do them. So my pain MD and surgeon have decided I probably need a morphine pump. I understand it means less drugs in my system and I may even have better pain control. Never am I pain free with oral narcotics. But the part I don't like is the drug is refilled by having a needle go through my abdomen into the pump every 1-3 months and having surgery every 5 years or so to change the battery. Anyone out there with long term experience with a morphine pump?