Lower esophageal sphincter abnormality: The first is abnormally weak contraction of the LES, which reduces its ability to prevent reflux. The second is abnormal relaxations of the LES, called transient LES relaxations. They are abnormal in that they do not accompany swallows and they last for a long time, up to several minutes. These prolonged relaxations allow reflux to occur more easily. The transient LES relaxations occur in patients with GERD most commonly after meals when the stomach is distended with food.
Hiatal hernia: hiatal hernia may weaken the LES and increase the risk for gastro esophageal reflux.
Other Factors: Certain foods and beverages, including chocolate, peppermint, fried or fatty foods, coffee, or alcoholic beverages, may trigger reflux and heartburn. Studies show that cigarette smoking relaxes the LES. Obesity and pregnancy can also play a role in GERD symptoms.