We investigated the mechanism of postoperative gastric stasis following pylorus preserving pancreatoduodenectomy (PpPD) with two experimental models. First, the duodenum transection and re-anastomosis was performed at 1 cm (group I), 2cm (group II) and 4 cm (group III) distal to the pylorus to interrupt the intramural neural pathways in rats, and then gastric emptying was measured with the phenol red method at 2 or 4 weeks after surgery and neuronal nitric oxide synthase (nNOS) containing neurons in the duodenal myenteric plexus were examined immunohistochemically. Second, the pancreatoduodenectomized dogs were divided into two groups of the pylorus preserving (PP) and the pylorus partial resection (PPR) by means of the duodenojejunal reconstruction, and then gasric emptying was measured with the acetaminophen method at 2 and 4 weeks after surgery.
In duodenum transected rats, there were no significant differences between gastric emptying of group III transected distal to the papilla of Vater and normal controls, whereas both of group I and group II transected oral to it showed significantly delayed gastric emptying (p<0.05) and the increase of nNOS containing neurons in the distal and the decrease of those in the oral to the anastomosis. In the PpPD dogs, the pylorus preserving group showed significantly delayed gastric emptying compared with the partial resection group or preoperative controls. These results suggest that the decrease in nNOS containing neurons due to the transection oral to the papilla of Vater causes delayed gastric emptying and may be related to postoperative gastric stagnation following pylorus preserving pan-creatoduodenectomy.

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The symptoms of urgency, diarrhea and nausea are exhibited in inflammatory bowel disease such as ulcerative colitis. The correlation among the changes of motility in gastrointestinal tracts and the symptoms were investigated using a model of acute colitis in ten dogs. Colitis was induced by acetic acid and the motility in gastrointestinal tracts was recorded with strain gauge transducers. The dogs exhibited urgency and diarrhea with mucus and blood during colitis. At the same time, the motor activity of the colon and stomach changed during colitis: 1) the incidence of colonic motor complexes (CMCs) were significantly decreased ; 2) the total duration per hour and mean duration of CMCs also decreased significantly ; 3) the incidence of giant migrating contractions (GMCs) increased significantly ; and 4) interdigestive migrating complex (IMC) of the stomach was disrupted and changed to irregular pattern. The response of colonic motility to a meal during colitis was also investigated. As the result, 1) the incidence of CMCs had a tendency to increase in the early postprandial periods in the proximal and distal colon and 2) the incidence of GMCs had similar effects to the incidence of CMCs. These findings may indicate that Gastro-Colonic Response during colitis, similarly to the normal colon, remains. There was no significant difference between the cleansed and uncleansed colon during colitis or in the normal colon. On the other hand, there was significant shortening of the mouth to caecum transit time during colitis. In conclusion, the changes in gastric and colonic motor activity, including the shortening of the mouth to caecum transit time, may be related to the abdominal symptoms accompanied by acute colitis. Moreover, the change of colonic motility including CMCs and GMCs in the early postprandial period indicates a close correlation between worseing of abdominal symptoms and up-take of meal.

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