I have recently started to feel Nauseous/unwell after eating meals, meals like Oatmeal, or meals containing bread with beans, I eat them and I feel nausea and sometimes light headed, unwell, then it slowly calms down after 1 hour and the level of Nausea and feeling unwell decreases, just wondering if this is a sign of IBS  or a gluten sensitivity issue? I don't feel any pain in my gut, no blood in stools, no diarrhea, no constipation. This problem has just started very recently, I've been eating bread, oats, for years and never had a problem before, I do have a history of antibiotic use and had a Parasite infection in April, maybe this has something to do with it ? 

 

I think many people go through periods of what you describe. The most likely cause is untreated post-nasal drip; aka too much snot.  Or simply over-eating.  Anxiety/emotional upset is another common cause.  IBS is linked to anxiety, but does not apply here since as the name implies.  You might want to try probiotic yoghurt.