Our Vet will be answering your question for you, but I think he may need some more information. I have dogs but have had cats in the past and can honestly say that I have seen this behaviour in perfectly healthy cats. Additional information you could add is like is this after meal times? or is it any time of day? Does this happen after the cat has been outside? Are the cries really discomfort or just sheer pleasure at rubbing the tummy on the floor?
If the cat is irritated they will normally use their tongues rather than scrape along the floor, unless its internal. Cats can get upset bellies like us, and really dry food is one cause. Like I said our vet will be able to throw some professional advise your way.