Is having a gastric bypass safe and what are the disadvantages if any....?

Some risk: Modern gastric bypass surgery is much safer than it used to be, with a risk of death around 1% and other complications around 40%. The risk seems to be worth it though because the risk of death after successful surgery goes down 89% over five years. So if 100 people have gastric bypass, about one will die from the surgery, but 89 will survive longer than they would have without the surgery!

Actually No, Several: Gastric bypass, roux-en-y, most common, see on youtube, is major surgery with associated major risks (including death), scars, etc. To reduce addictive behavior. People often better short term but long term malnutrition problems & other addictions; no cure. Better learn more about addiction & change food choices, see nusi.Org. Consider victoza (liraglutide) +/- symlin & many other far safer self-change options.