For many years, gastroenterologists have searched for the holy grail of pancreatic function tests—the tubeless test. The quest is to find an accurate, simple, easy, sensitive, and specific non-invasive test that can detect mild to moderate decreased exocrine function in patients without signs of pancreatic disease on imaging tests. Such a test would increase the possibility of diagnosing early chronic pancreatitis and perhaps pancreatic cancer as pancreatic function may decrease in pancreatic diseases before imaging tests become abnormal. However, tests based on decreased exocrine function can never be one hundred per cent sensitive for the diagnosis of chronic pancreatitis; even some patients with pancreatic calcification, a recognised hallmark of advanced chronic pancreatitis, have normal exocrine function.1

Generally, modern tubeless tests satisfactorily distinguish pancreatic from non-pancreatic malabsorption as they are sensitive indicators of pancreatic disease when pancreatic function is severely decreased. However, for pancreatic insufficiency to be severe enough to produce malabsorption, secretion of pancreatic enzymes must be 5–10% or less than normal.2 ,3 In this case, pancreatic disease is advanced and the diagnosis often is obvious by other means. Therefore, tubeless tests are highly sensitive only when malabsorption is present and generally are not a useful clinical test with which to make the diagnosis of chronic pancreatitis.

The foundation of non-invasive tubeless tests rests on decreased pancreatic function increasing the amounts of unabsorbed food (fat, protein, carbohydrate) in stool or decreasing the amount of enzymes (for example, chymotrypsin, elastase, amylase, lipase) in the blood or faeces. Compounds also have been designed and synthesised that are hydrolysed within the gut lumen by pancreatic enzymes. Use of these compounds as pancreatic function tests is based upon measuring decreased amounts or concentrations of the products of the synthetic …