Gastroesophageal reflux disease

Factors that have been linked with GERD but not conclusively:

Obstructive sleep apnea
Gallstones which can impede the flow of bile into the Duodenum which can affect the ability to neutralize gastric acid

Foods
Certain foods and lifestyle are considered to promote gastroesophageal reflux:

Coffee, alcohol, and excessive amounts of Vitamin C supplements stimulate gastric acid secretion. Taking these before bedtime especially can cause evening reflux. (Although a study published in 2006 by Stanford University researchers indicates there is no published evidence of dietary changes benefiting those with GERD.
Antacids based on calcium carbonate (but not aluminum hydroxide) were found to actually increase the acidity of the stomach. However, all antacids reduced acidity in the lower esophagus, so the net effect on GERD symptoms may still be positive.[7].
Foods high in fats and smoking reduce lower esophageal sphincter competence, so avoiding these tends to help. Fat also delays stomach emptying.
Eating within 2-3 hours before bedtime.
Large meals. Having more but smaller meals reduces GERD risk, as it means there is less food in the stomach at any one time.
Carbonated soft drinks with or without sugar.
Chocolate and peppermint.
Acidic foods, such as oranges and tomatoes.
Cruciferous vegetables: onions, cabbage, cauliflower, broccoli, spinach, brussels sprouts.
Milk and milk-based products containing calcium and fat, within 2 hours of bedtime.