Hi @luft80, welcome to Mayo Clinic Connect. It is difficult to watch your child deal with health issues especially when you do not know how to help them. He must be discouraged having needed a blood transfusion that does not necessarily fix his problem, not knowing where to look for help.

I am tagging @astaingegerdm, @epvb who created this discussion about collagenous gastritis and @tc4334 who mentions their daughter dealing with this same condition for over 10 years. They may have updates that will help.

This 2016 research information from Mayo Clinic is about budesonside that other members have commented about trying, “ TTB therapy produced clinical and histologic improvement after other therapy had failed.” One thing I like to check out is the names listed at the top of the document, learning more about the people who put this research together may provide more information for you: https://mayoclinic.elsevierpure.com/en/publications/collagenous-gastritis-characteristics-and-response-to-topical-bud

I do not have collagenous gastritis but I am familiar with Mayo Clinic in the US as a GI patient as well as other areas, and would highly recommend them. I worked with doctors local to me and did not make progress. Once I was evaluated at Mayo Clinic in Rochester I was told they knew what was happening with me but did not know what to do about it. They wanted to work with me to first, protect my heart and then take one symptom at a time. We have been doing this for several years. They tell me something to do, I do it, I incrementally improve. GI is a big part of my care. I would describe Mayo as conservative in their approach and aggressive to treat once they are confident. https://www.mayoclinic.org/about-mayo-clinic/quality/top-ranked
- Contact Mayo Clinic to discuss an appointment: http://mayocl.in/1mtmR63
- Then work with International Patient Services https://www.mayoclinic.org/departments-centers/international

Their location in London may be an option as well since you are in Spain.
- Mayo Clinic in London: https://www.mayoclinichealthcare.co.uk/

You mention a transfusion followed up with iron tablets is currently controlling your son’s CG. How is his day-to-day affected by all of this? How are you doing, mom?