Stomach distension, retching, vomiting. What's going on?

Stomach bloating, retching, vomiting, considered to be caused by indigestion, mostly caused by overeating, eating greasy food and other factors. Secondly, considered to be caused by gastritis, and Helicobacter pylori infection, excessive drinking, taking non-steroidal anti-inflammatory drugs and other factors. In addition, gastric ulcer, duodenal ulcer and other diseases, also will appear stomach bloating, retching and vomiting symptoms. In addition, also cannot rule out is the plant nerve function disorder causes, with psychological pressure big, the mental tension, the heredity and so on factor is related.