There are many symptoms of ME/CFS and everyone will experience different illness pattern relating to them. For example one person can have crippling headaches but someone else won't be too badly affected by them.
However there are core symptoms and secondary symptoms associated with ME/CFS. The core symptoms everyone with ME/CFS will experience to one degree or another. The secondary symptoms are what many will have and sometimes these can be very disabling. In fact, there are over a 100 different symptoms listed, but that doesn't mean everyone will experience every symptom.
There is no doubt that ME/CFS/FMS can cause symptoms that maybe at first don't seem to be part of the illness and in many cases that's true.
However possibly in a minority of cases things like Seizures (Epilepsy attacks), Auto-immune problems, thyroid problems and Gilbert's Syndrome are found in ME.
It's not for this site to say whether there is a link between ME and these problems but it does seem to happen more frequently.