Yes, I often wonder if it's because of the fatigue xc

Hi Lucy6, Do you notice the nausea after eating any particular food? Are there any other symptoms with it - like pain, headache, dizziness, bloating?
I have histamine intolerance (google it) and lots of foods make me nauseous - but not immediately. There is a gap of perhaps an hour or so, and then I can get dizzy, bloated, or other lovely (NOT!) symptoms. I have to now watch what I eat, and take a truck-load of supplements as well.
If you are not histamine intolerant, then perhaps you could take a digestive enzyme or even an antacid or the like as it may be caused from an over-acid stomach. Lots of things it could be. Check in with your GP if it keeps going. All the best with this.

I've been having this since November 2023. I've been sent for a gastroenterology test as it's not normal. Dr said it might be the medications I take for fibromyalgia and spinal Stenosis.

What helps is orange juice after eating or eat in small amounts or peppermint tea.

I used to get this when I was working and still sometimes do feel nauseous just before bed. Peppermint tea helps

If you feel its fatigue related, I've just completed a CFS programme and I was advised to eat little and often, even if that means having 6 small meals a day. Me personally had this years ago when I was first diagnosed with fibro and the only thing I could eat was cereal for weeks, the thought of anything else knocked me sick