I have fed complete for lots of years. now my dogs are fed raw. my question is, has anyone ever done research on whether raw or complete increase the risk of 'bloat'?

I have known dogs to Bloat regardless of feeding and following guidelines.  I believe you can lessen the chances (exercising before/after feeding, etc) but I think if it's going to happen, it will regardless of what the dogs fed.  Some really crappy kibble swells by massive amounts though(Beta is well known for this) and I don't imagine this is easy on a digestion.

I have fed complete for lots of years. now my dogs are fed raw. my question is, has anyone ever done research on whether raw or complete increase the risk of 'bloat'?

There was one of the US uni's did quite a bit of research on bloat but offhand I cannot remember which one, as far as I remember there were no suggestions on your question either way, if there was I would certainly remember 'cause my breed is predisposed to it - if your on any US pet or other dog forums they might be up on any current advances in knowledge if there are any.

Dogs on raw came out as less likely to bloat from my readings however it still seems to be multifactorial and not guaranteed

It was Purdue Uni did studies on GT, heres some info from their site, there maybe more I dont know.

http://www.instituteofcaninebiology.org/bloat-purdue-study.html
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Aparentley the reason dogs get bloat is when dogs eat from the floor and suck up to much air into their stoamchs while eating.
The cure is to feed your dogs from raised bowls that are at a higher level and as said before only feed your dog after exercise when they are calm.

Hope this helps.

and other research says that raised feeding promoted bloats, so who knows.