If you undergo a partial gastrectomy , you can expect to: Stay in the hospital for 3 – 5 days after surgery Have some weight loss for 4 – 6 weeks Resume normal eating patterns 3 – 6 months after surgery If you undergo a total gastrectomy , you can expect to: Stay in the hospital for 5 – 8 days after surgery Have weight loss for at least 2 months Adjust to a new diet as your digestive system heals Many people experience symptoms of dumping syndrome after gastric surgery. This happens shortly after eating when food enters the intestine too quickly. Symptoms include: Cramps in the abdomen Pain Diarrhoea Lightheadedness