I am having no luck with googling!
About two or three times a month I feel sick - I never throw up, but just feel very nauseous. It's not linked to my cycle, but is possible triggered by certain foods. I've been keeping a food diary and the nausea sometimes appears to be triggered by wine, cheese, roast chicken, cream and once a lamb tagine! However, I don't get nauseous every time I eat/drink these foods, so not sure if it's anything to do with them.
I sometimes gets indigestion before the nausea, but not always. When the nausea is subsiding I sometimes get a slight gnawing feeling under my breastbone. I very occasionally get mild heartburn and IBS-like symptoms. The nausea is completely relieved by lying down and made worse by sitting bent forward or wearing a tight bra 
Have wondered about gall bladder, but have no real pain.
Please tell me it's not just part and parcel of being 50!