PROBLEM TO BE SOLVED: To provide a method for producing a model animal which develops chronic pancreatitis and diabetes from reduced glucose tolerance and insulin resistance after ablation of the pancreas.SOLUTION: A method for producing a model animal of exocrine pancreatic insufficiency comprising the steps of: (a) cutting a pyloric portion of the stomach and a duodenum portion into which pancreatic juice flows (b) cutting a proximal jejunum of the anal region from the treitz ligament which is a boundary of the duodenum and the jejunum (c) closing the anal side cut end made by the step (a), and anastomosing the anal side cut end of the jejunum made by the step (b) and the stomach side cut end of the duodenum made by the step (a) [duodenum-jejunum anastomosis] (d) connecting and anastomosing the duodenum side cut end of the jejunum made by the step (b) to the incised rectum part [small intestine-rectum anastomosis] and (e) applying intubation to the common bile duct, the duct connecting the gallbladder and the duodenum, to connect and anastomose to the small intestine part in the step (c) [common bile duct-jejunum anastomosis].
