In chronic pancreatitis chronic inflammation of the pancreas results in irreversible injury and fibrosis. The most common causal factor is excess alcohol consumption. Smoking is an independent risk factor. Gene mutations can lead to hereditary chronic pancreatitis and idiopathic disease, where no clear cause can be identified, accounts for 20-30% of cases. The typical presenting symptom is intermittent or continuous upper abdominal pain which may radiate to the back. The pain is commonly triggered or exacerbated by eating or alcohol consumption.