That's interesting, but for me not the case. In fact, I have a genetic liver disease that hasn't been at all affected by the PCS. I have had no more flareups after head injury (06/07) than before. I am very careful about the drugs that my neurologist prescribed (which are plenty!) though.
It could be that you've had a condition all along, but you're worn down from the PCS. My liver flares when I've overdone it (working too many hours, etc.) Stress will also cause my liver to flare- and I can honestly say that the PCS has been very stressful for me at times.
Blessed are the cracked, for they shall let in the light.
~ Groucho Marx