It is not normal. Are you taking anything such as Nexium. If not I suggest you ask your doc if he thinks it will help. If you are taking something, maby you need a different medication. Often after gallbladder removal people are on Nexium or some other proton pump inhibitor for life.
Are you constipated? If you are not having good bowel movements you could either be contipated or have an obstruction which could also cause nausea and vomiting. but I am sure that your MD would have questioned that. If you were taking a lot of pain medication after the surgery the pain medications are very constipating.
If the doctor does not find the cause, I would recommend that you get a second opinion from another GI doctor.
Hope you feel better soon!