How do you sleep after gastric balloon: After the first few weeks, you should be cleared to sleep normally. This means sleep on your back or on your side. Back or side sleep will allow your body’s natural digestive processes to function while you are resting.If it doesn’t matter which side you sleep on, then your left side is the best side to sleep on as some studies show that it reduces reflux. Importantly, either side is fine as long as you’re comfortable.