Hi Ali, I have heard about implant illness, more so on US blogs than UK. I remember when I asked about implants on a different site before my surgery and someone mentioned it and had theirs removed but the symptoms persisted. There are many causes of general fatigue/sore throat symptoms as well like many of the viral illnesses, autoimmune etc., so it may well be due to something else. There’s no scientific link between implants and illness and no diagnostic test for it, so the ultrasound will mainly be looking for problems with the implants themselves, like lumps, cancer, a silent rupture/ leak etc. in which case they would likely be need removal. But if the US scan shows nothing, then they will likely leave it to you to decide.
I don’t know if Allergan natrelle implants have anything to do with it unfortunately, but mentor seem to be more widely used now.