The pancreas can be studied for obstructive disease by measuring serum lipase levels in the two stage provocative test. The test is nonspecific but noninvasive and applicable to all stages of pancreatic diseases. In this test, the pancreas is stimulated twice in two hour intervals before measuring the serum enzyme levels: first, with pancreozyin and secretin--the stage 1 test and, second, with pancreozymin, secretin, betazole hydrochloride and morphine sulfate--the stage 2 test. Among the pancreatic enzymes measured, lipase was most reliable. Serum lipase level elevation in the stage 1 test indicates a pancreatic abnormality and it completes the test. Patients who fail to respond to the stage 1 test have either a normal pancreas or pancreatic insufficiency and need the stage 2 test for differential diagnosis. In the stage 2 test, the serum lipase level is elevated in patients with a normal pancreas but not in those with pancreatic insufficiency. As a preliminary study, ten patients with carcinoma of the pancreas, two with pancreatitis and ten in the control group were studied. All patients with a known pancreatic disease demonstrated an abnormality in the test. Two of ten in the control group also had abnormal results. The two stage provocative test may be used prior to undertaking more invasive examinations, such as an arteriogram, in patients who are suspected of having pancreatic disease, yet other tests have failed to indicate it.