Hi there ~ Gastric bypass is surgery that helps you lose weight by changing how your stomach and small intestine handle the food you eat. After the surgery, your stomach will be smaller. You will feel full with less food. The food you eat will no longer go into some parts of your stomach and small intestine that break down food. Because of this, your body will not absorb all of the calories from the food you eat. You will have general anesthesia before this surgery. You will be asleep and pain-free. There are two steps during gastric bypass surgery: The first step makes your stomach smaller. Your surgeon will use staples to divide your stomach into a small upper section and a larger bottom section. The top section of your stomach (called the pouch) is where the food you eat will go. The pouch is about the size of a walnut. It holds only about 1 ounce of food. The second step is the bypass. Your surgeon will connect a small part of your small intestine (the jejunum) to a small hole in your pouch. The food you eat will now travel from the pouch into this new opening into your small intestine. Because of this, your body will absorb fewer calories. Gastric bypass can be done in two ways. With open surgery, your surgeon will make a large surgical cut to open up your belly. Your surgeon will do the bypass by working on your stomach, small intestine, and other organs. Another way to do this surgery is to use a tiny camera, called a laparoscope. This camera is placed in your belly. The surgery is called laparoscopy. I wonder if you are talking about bypass surgery of the heart. If that is the case, then a cardiologist would be the right person to contact regarding the feeding tube and wean him off of the food being given intravenously. I hope this helps. Take care and have a lovely day!