Repeated inflammation of the pancreas causes scarring and destruction of the pancreas. Normally, the pancreas makes digestive enzymes and the hormone insulin. When the pancreas is damaged, lack of digestive enzymes can cause diarrhea and weight loss due to poor digestion. Lack of insulin can cause diabetes. Chronic pancreatitis can cause constant pain in the abdomen. The most common cause of chronic pancreatitis is heavy alcohol consumption.