The ones I have seen all seem to have been caused by giving live birth (these were hissers not Dubia though - not sure if that is significant). They were all female and all had the prolapse immediately after giving birth, I believe as a direct consequence of it. Two were really bad cases and the female died within a couple of days, but another female had a very small prolapse (significantly I think there was no sign of the 'tubes' described by the OP in this case which I believe means her gut and internal organs were not significantly damaged) and that one seems to have fully recovered, but now seems unable to make a viable ootheca and hold it to term.
I don't know whether the births were premature and caused by stress, though I would doubt it at least in one case as the second fatal prolapse occurred several months after I'd got this female and she had settled in with the others and was eating well, and didn't seem distressed in any way. Whether some other damage or injury had occurred to these females in transit (I got all of them as adults, they were not born in my colony) I don't know and as yet I have not had any births from my new adult females who were born and matured in my colony, so I can't really pinpoint the reason. It's possible my original females were just old and therefore more likely to suffer a prolapse anyway.
Sometimes it falls off and they recover, most of the time they die though.
