What makes us nauseous?

Its so weird. What actually makes us nauseous after we eat sometimes. I used to get it really bad the first few months. I had to take motion sickness pills just to curb the nauseousness. I will be 1 yr post op on the 20th and just last evening i got that feeling right after supper. Nauseousness and then suddenly very sleepy. What causes that????????

Sounds like a form of dumping to me....It could be the fat content, or even a bit of lactose intolerance! You could also be eating too fast! Unfortunately this knowledge comes from personal experience