Oesophagitis. Illustration of the human stomach depicting reflux oesophagitis, an inflammation of the oesophagus. Reflux oesophagitis is caused by poor functioning of the muscles of the lower oesophagus, which permits reflux (regurgitation) of the stomach's acidic contents into the oesophagus. Acid is seen erupting from the wall of the stomach, resulting in the formation of a peptic ulcer. This condition may be associated with a hiatus hernia, where the top part of the stomach slides back and forth between the chest and the abdomen. The main symptoms of oesophagitis is heartburn, which may be worsened by smoking, drinking alcohol or by obesity.