In a curative resection for advanced sigmoid or rectal cancer, an extensive dissection of the regional lymph nodes is generally required. This often necessitates the removal of the autonomic nerves around the inferior mesenteric artery. The present study was done in an attempt to clarify the influence of a neurectomy around the inferior mesenteric ganglion and plexus on the motility of the colon. In eight dogs, we resected the ganglion and plexus around the inferior mesenteric artery, together with an implantation of strain gauge force transducers in various parts of the colon, and 7-10 days later, colonic motility was examined. The percentage of contractile states and contractile forces increased at both the distal colon in fasting dogs, as well as at the middle colon in the late postprandial period. At the distal colon, contractile forces were noted in the early and late postprandial periods. These contractile abnormalities at the middle and distal colon may thus explain the frequent bowel movements or diarrhea often observed after extensive surgery in patients with sigmoid or rectal cancer.

We investigated the efficacy of transabdominal ultrasonography for the diagnosis of advanced colorectal cancer. Colonic examination by colonoscopy, barium study, or surgery was carried out in our institution on 1579 patients during the past 5 years. This study focused on 1564 of these patients, 15 who has been diagnosed with colorectal cancer before ultrasound examination having been excluded. The results included 51 ultrasound-positive cases, 9 ultrasound-false-positive cases, 1476 ultrasound-negative cases, and 28 ultrasound-false-negative cases. Sensitivity was 64.6 percent and specificity was 99.6 percent. Of the 28 ultrasound-false-negative cases, the lesion was detected in the ascending colon in 2, in the transverse colon in 6, in the descending colon in 1, in the sigmoid colon in 3, and in the rectum in 16. Obstruction and dilatation suggested colorectal cancer in 3 cases, which were thus classified as ultrasound-negative when no tumors were detected. Sensitivity was investigated by site. Sensitivity was lowest at 30.4 percent in rectal cancer, but was 78.6 percent in colon cancer, exclusive of rectal cancer. Laboratory findings and clinical symptoms which were suggestive of colorectal cancer were used as information before ultrasound examination was performed. Sensitivity of examinations carried out on examinees on whom prior information was available and on those on whom there was no information did not differ significantly. Furthermore, ultrasound was thought to detect approximately 65 percent of advanced colorectal cancers when it was used aggressively to investigate the large intestine. Ultrasound was thus considered effective for detecting advanced colorectal cancer.

Previous studies have suggested that enterohepatic circulation of bile acids is essential for regular cycling of duodenal migrating motor complexes (MMCs). The present study was an attempt to clarify the role of bile acids in the enterohepatic circulation system in initiating duodenal MMCs. Seven dogs underwent total external biliary diversion that resulted in the loss of MMCs originating from the duodenum. Sodium ursodeoxycholate (6 mg/kg/hr) was then given either through the portal vein or a peripheral vein, and motility of the gastrointestinal tract was serially recorded. When sodium ursodeoxycholate was given either through the portal vein or a peripheral vein during external biliary diversion, duodenal MMCs restarted. The cyclic change in plasma motilin levels during an MMC cycle as induced by sodium ursodeoxycholate was almost the same as in a normal MMC cycle. Total bile acid concentration in the portal vein changed cyclically with MMC cycles when bile flow was intact but did not change cyclically with MMC cycles restarted by intravenous bile salt infusion. Bile acid stimulation of putative receptors existing between the portal vein and intrahepatic bile ducts may be involved in initiating normal duodenal MMC cycles.

The findings of ultrasonography are useful for diagnosing and determining the treatment of PDU.

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