So, of course, I'm doing all the googling. Amongst others, I have learned these two things:
With exception of the Roman Catholic Church, most mainline Christian churches offer their communicants gluten-free alternatives to the sacramental bread, usually in the form of a rice-based cracker or gluten-free bread. These include United Methodist, Christian Reformed, Episcopal, Lutheran, The Church of Jesus Christ of Latter-day Saints, and many others.
Roman Catholic doctrine states that for a valid Eucharist the bread must be made from wheat. [...] On August 22, 1994, the Congregation for the Doctrine of the Faith apparently barred coeliacs from ordination, stating, "Given the centrality of the celebration of the Eucharist in the life of the priest, candidates for the priesthood who are affected by coeliac disease or suffer from alcoholism or similar conditions may not be admitted to holy orders." After considerable debate, the congregation softened the ruling on 24 July 2003 to "Given the centrality of the celebration of the Eucharist in the life of a priest, one must proceed with great caution before admitting to Holy Orders those candidates unable to ingest gluten or alcohol without serious harm."
In patients with an aggressive, evolving polyneuropathy or a specific paraneoplastic syndrome, additional testing for an occult malignancy is often performed(my bold - am I possessed by some kind of ghost with cancer?!)
More seriously of course, it is good to finally have a diagnosis. Just need to try and get to the bottom of what's causing it, to be able to find out if it can be treated.