Nausea is the very unpleasant feeling of being about to vomit. Vomiting is the expulsion of the contents of the stomach. It's associated with a feeling of nausea and strong contractions of the abdominal muscles. Vomiting is different from regurgitation, in which one spits up stomach contents into the esophagus without feeling sick and without strong muscle contractions.
A splenectomy is surgery to remove the entire spleen, a delicate, fist-sized organ that sits under the left rib cage near the stomach. The spleen is an important part of the body's defense (immune) system. It contains special white blood cells that destroy bacteria and help the body fight infections when you are sick. It also makes red blood cells and helps remove, or filter, old ones from the body's circulation.
If only part of the spleen is removed, the procedure is called a partial splenectomy...
Vomiting -- especially if it comes with diarrhea -- can cause dangerous dehydration. This is more likely to happen to children. When caring for a sick child, be alert to symptoms that mean the child needs water: dry lips and mouth, sunken eyes, rapid pulse, rapid breathing, and, in babies, a sunken look to the soft spot on the top of the head and no wet diapers.
Sometimes the cause of nausea and vomiting is psychological. This doesn't mean the symptoms aren't real. A qualified clinical psychologist or psychiatrist can help. People who often make themselves vomit may have an eating disorder. This can be a life-threatening condition. If you eat a lot and then make yourself vomit, you need professional help.