The goal of this interventional study is to learn if carbohydrates loading improves overall outcome in adolescent patient undergoing scoliosis curgery The main questions of the study are as follows: 1. Does carbohydrates loading improves gastrointestinal related problems such as improvement in return of bowel function measured by first passage of flatus, reduce constipation by patient's time to first bowel opening and reduce incidence of post post operative nausea and vommiting 2. Does carbohydrates loading reduces length of hospital stay and patient's overall condition in term of anxiety, thirst and hunger 3. Does carbohydrates loading affects gastric residual volume by measuring residual gastric volume with ultrasound