Can there be such thing as physiological bulimia?

Yes and No: Bulimia nervosa has both a physiological and a psychologic component. If you are asking if people purge with vomiting automatically without self-inducing, yes that can happen as a conditioned response, but not due a autonomic physiological condition. If this is occurring a medical work-up is required as the diagnosis is not likely bulimia. Hope this helps clarify a bit.