Ever since September last year I keep getting these times were I've got an upset belly, general nausea and trouble eating. Also feeling weak and really don't like being too hot. It only lasts for about a week and then I'm fine. The last time this happened was mid-January and I thought it might be the last time, but I've just spend this last week unwell again with the same symptoms, just starting to feel a little better today. Does anyone have any idea what this could be?