3. The third aim of the study is to study the physiologic mechanism of action of rTMS in these patients using magnetic resonance imaging (MRI). In doing so, the researchers aim to contribute to a better understanding of the pathophysiology of chronic pain in patients with pancreatitis by investigating the correlation between pain improvement and areas of brain activation. This could lead to the development of markers of therapeutic response. Magnetic resonance spectroscopy allows a non-invasive measure of GABAergic and glutamatergic activity in a defined volume of interest in the brain. The researchers hypothesize that the balance of GABA and glutamate will be abnormal in SII in patients with pain from chronic pancreatitis, with a relative decrease in GABA and increase in glutamate indicating an abnormal, hyperexcitable dysfunction. This abnormality will be normalized by rTMS in correlation with its analgesic effect.