Some people are born with a naturally weak sphincter (LES). For others, however, fatty and spicy foods, certain types of medication, tight clothing, smoking, drinking alcohol, vigorous exercise or changes in body position (bending over or lying down) may cause the LES to relax, causing reflux or the accidental back-up of acid. A hiatus hernia (a common term for heartburn) may be present in many patients who suffer from heartburn (GERD), but may not cause symptoms of heartburn.
