HELP ME UNDERSTAND

I was reading in my ins booklet, can anyone help me to understand what they are saying?

GASTROENTEROSTOMY,    gastric stapling, OR by-pass and section assisted lipectomy (relating to treatment of obesity) or related surgical procedures.

If anyone can help me understand this I will grateful.
God Bless
Evie

How about this:

surgical creation of a connection between the stomach and the jejunum. The operation can sometimes be performed at the same time as a partial gastrectomy (the removal of part of the stomach). Gastroenterostomy was in the past typically performed to treat peptic ulcers, but today is usually carried out to enable food to pass directly to the small intestine, bypassing a damaged duodenum. The procedure is becoming less common, due to advances in the treatment of ulcers, new antibiotics and drugs.