my 10-month old has just had an operation to remove a stone from her colon. Now recovering well, it appears, but we have been totally distraught and I am now really worried about the future. She never eats stones in front of us - it is something she started as a really small puppy and I followed advice to get her to stop by being really firm about it, and it worked. Then a few weeks back she threw up a small pile of stones - well, sort of regurgitated in fact - but was otherwise OK. Vet looked at her and all was well. This happened two more times and on the third occasion the vet found a big stone obstructing her. Despite me watching her like a hawk, it seems she still picked up, so how am I going to stop her? At the moment she is in the house or on a short lead at all times - OK for now as she still needs to be quiet, but she's already frustrated and a bit depressed so I will need to find ways of letting her run free again. Is a muzzle the only answer? Or has anyone had any success in training out of this behaviour?

I've never had any success in stopping mine from doing it, even at 2 years old I still find all sorts in her *deposits* - stones, carpet, vetbed, plastic, brick, wood etc. No matter how hard I try she always manages to find some from somewhere :(
A friend of mine had a very, very poorly dog a couple of months back, thought she was going to die. Vet eventually found a stone obstruction and now thankfully she is fit and well again. Glad to hear your girl is ok.

We've never been successful at stopping ours eating stones either.  Just try to minimise it as much as you can.  If they are that determined they will find one to eat somewhere.