There are many documents and websites which mention the Schilling test for Pernicious Anaemia. Look on TUK here and on the PAS forum and you find no-one seems to have had it in recent years.
The paper below is the first time I have found an actual reason, other than cost, for it not being available. Have already posted the link over in PAS but thought it could be of some interest here as well:
© 2007 American Society for Nutrition
The Disappearance of Cobalamin Absorption Testing: A Critical Diagnostic Loss1
Department of Medicine, New York Methodist Hospital, Brooklyn, NY 11215, and Weill Medical College of Cornell University, New York, NY 10021
When the manufacturer of the most popular Schilling test kit (Dicopac, Amersham Health) discontinued its licensing in 2003, mainly because of concerns of potential transmission of bovine spongiform encephalopathy via its animal-derived IF dose, much of the medical community's reaction was muted. In fact, requests for the test, whose costs exceeded reimbursement by health insurers, were already in decline. I know of no American manufacturers who provide radioactive cobalamin test doses or IF today.
As to cost - well there are many claims that the cost of a single Schilling test exceeds that of life-long monthly B12 injections.