Perhaps speak with HR.  you should have no problem finding quality doctors in Germany. If it's a new job with a completely new employer, than speaking to HR not such a good idea.  Try google.  You should be able to find a gastro person near where you are going.  And if the information is not in English use google translate.  Good luck with all!

You might try contacting the Cleveland Clinic to see if they have the names of any specialists who live/work in the Frankfurt area and are familiar with J-pouches, etc.  Prior to a trip to Asia I contacted a specialist at a major IBD center in California and elicited the names of colorectal surgeons in the area to which I was going to travel.....just in case I needed someone.  Best wishes!

First step is to speak with your employer about recommendations and how to navigate the insurance system. Next step(s) would be to research through the insurance company their policies, providers, etc. And also check out sites such as Expatica for help and recommendations specific to your area. As soon as you can, go on google and search for local expat groups; also try FB. These groups are INVALUABLE in navigating your new country!

We live in the Netherlands, so the system is different, but I can tell you that I have NEVER had a problem getting care with an English-speaking provider, whether it has been the GP, a surgeon, physical therapy, etc. In a place like Frankfurt I highly doubt you'll have a problem either.

Do realize that medical approaches vary culturally from what you're used to; this is where insights from other expats is very helpful. The first time I went to a Dutch doctor who, in response to my description of the problem, asked, "And what do you think we should do?" I nearly fainted. Took some getting used to the different approach, for sure! (Having said that, I actually now prefer the Dutch approach over both the Canadian and American...)

In order to find the appropriate specialist/surgeon (if necessary), you will probably have to go through an Internist rather than the GP; this should not be a problem. Europeans in general take preventative care very seriously, and they prefer that their patients are proactive in managing their health. Once you get an appointment with an Internist (GI specialist; you'll have to see the GP first to get a referral), he or she will know the best doctor/hospital for treatment. Again, my experience here is that they do not hesitate to send you to the best place/person, recommend second opinions, explore options and alternative therapies, etc.

And if worse comes to worst, I can recommend my current surgeon (in Amsterdam) who is one of the top two J-pouch surgeons in Europe.

Cheers, and have a great time!

Gin