Relationship between pancreatic function and pain in chronic pancreatitis.

The association between pain and exocrine pancreatic function was re-evaluated in 56 patients with chronic pancreatitis to see if residual function of the gland may evoke outflow obstruction resulting in pain. No significant differences were found in the degrees of pancreatic dysfunction among three groups with different degrees of pain (no pain, n = 7; moderate pain, n = 21; and severe pain, n = 28), but patients with more impairment of exocrine pancretic function tended to have less pain. In patients with no pain the mean (SD) peak serum concentration of fluorescein was 2.0 (0.2) micrograms/l, in those with moderate pain it was 2.6 (0.1), and in those with severe pain it was 3.4 (0.1). No significant differences were found between the degree of pain and the duration of the disease, which was 5.5 (0.3) years in the group with no pain, 3.5 (0.2) in patients with moderate pain, and 3.8 (0.1) in those with severe pain. We conclude that outflow obstruction may affect some patients, but is not the only cause of pain. Patients with severe pancreatic dysfunction and steatorrhoea often present with pain, so either obstruction of the residual secretions, or inflammatory activity impinging on nerve endings in fibrotic tissue, may also cause pain. The causes vary, and there is often more than one, so optimal management implies thorough investigation of each patient and long term follow up.