Very interesting case. There is such a thing as somatic dissociation, certainly, and a person doesn't have to be DID to have it. If a person had chronic childhood illness with body pain, that could be dissociated in childhood and then associated in EMDR. An incomplete EMDR can continue for days.

On the other hand, maybe she had a coincidental sore throat.

In EMDR we always check to see at the next session how the work measures on SUD and VOC. If its resolving well, the EMDR is working. I wouldn't think, if the sore throat was somatic dissociation that kept percolating slowly after the EMDR, that the intensity of response would continue at that level.

When any client has a bad patch, its wise to regroup, restabilize, synthesize gains and so forth before proceeding to EMDR. I wouldn't let an intense session deter me if the client is actually functioning better and healing as a result of the difficult patch. If a client is getting worse I'd definitely back off EMDR until such time as the client is resourced and regulated affectively. My hunch is the client will be able to relate to the childhood memory of the physical illness differently now, and that the intensity won't repeat itself.

That's just a hunch, I don't have sufficient data though. So do please post back and let us know the outcome. Thanks.