Post Traumatic Stress is just that; still having trouble with significant trauma(s) that happened in the past. I don't think one has to experience flashbacks, the trauma can be more
"diffuse" than a single event. Being in a bad car wreck can get you flashbacks but abuse over quite a few years, there's no "one" thing to flashback to?

PTSD has degrees, too, like depression, anxiety or most other disorders. I use to get anxious eating ice cream cones (not something that usually makes someone anxious :-) and finally had a sense/flashback to my stepmother constantly scolding me for getting "dirty" and letting it drip on me, etc. I was too young to be able to eat an ice cream in one sitting without getting it all over me but my brother was a couple years older so he could. I'd be compared to him but there was nothing I could "do" about it. Having forgotten all about that, I was worried I wouldn't be able to eat my ice cream "fast enough" and would get in trouble. . . in my 40s :-) LOL

Now that I know what was causing my anxiety, I "practice" getting messy (don't like submarine sandwiches either because one gets mayonaise, etc. all over one's self :-) deliberately because I'm a grown up now and it "doesn't matter." My stepmother can't unlove me anymore, be dangerously angry or just make me feel anxious in general.

I think with dissociation, there's something "there" causing the dissociation so that's a traumatic stress if one is reacting to whatever it is in such a manner. It doesn't really change anything; I guess I'd personally feel better with a diagnosis of traumatic stress disorder instead of dissociative identity disorder especially if I didn't have a couple three identities well established. Traumatic stress just gives a locus of where the problems are probably coming from; outside one's self rather than from inside (which dissociation sounds like to me)? Dissociation, yes, everyone does it but it's a symptom, not an actual disorder; it can be part of PTSD.