Scoliosis is what's causing your acid reflux. Your spine is pathologically bent which is causing your diaphragm to endure excess pressure from your stomach and that's caused the sphincter opening of the diaphragm (called the hiatus) to become weakened and widened. The widening of the hiatal opening causes it to become incompetent in keeping the stomach pouch and its acidic contents down. This condition is called a hiatal hernia which happens when the stomach is pushed upward through your diaphragm and into your chest causing the acid from the stomach to reflux up the esophagus, throat, and mouth.