Without knowing your full medical history, it's hard to be clear on what is "normal". It sounds like you have already had the lap band surgery, is that correct?
From what I understand, it is a common thing for people to have stomach noises after the surgery- that said, you should notify your doctor about it as they will have some recommendations on how to help, depending on what exactly is the cause. Sometimes you just need to avoid certain foods and other times anti-gas medications help. In some cases, you might need to have a surgery done if they find that something isn't 'right' (for example an obstruction is found). Make an appointment with your doctor to be sure of what the cause is.