There is a problem with supply and since Sucralfate is used in hospitals after surgery it is prioritised and not easily available on prescription. My consultant gave me a prescription for the hospital pharmacy. Recently however I have obtained some from my pharmacy so maybe the supply is improving. I obtained some in the UK under a scheme where the pharmacist, (Lloyds) imports from elsewhere, in my case from Finland. You could ask the pharmacist in Spain if they have the same system and could obtain some from elsewhere. I understood that production is being increased as PPIs are not always favourable.
Interestingly this drug has shown recession of Barretts in a test.