We do DS' labs locally -- annual bloodwork and sputum/throat cultures and have the info sent to the clinic in the city. Usually time it a couple weeks prior to going to the City for a regular CF check. When DS has gotten sick, I've called the clinic in the City and have gotten a prescription sent to the pharmacy based on past cultures. Unlike our local CF clinic -- they actually call us back!
A couple years ago ds was vomiting, not stooling, was in pain so we took him to the local ER. They determined he had an obstruction, but based his complicated issues with meconium illeus as an infant, his doctor down there wanted us to head to the Children's Hospital in the city where they have SEVERAL pediatric surgeons instead of just the one at our local hospital. So we packed a bag and the next morning headed to the City.