Abstract
Bowel-transit times (BTT) and other bowel behaviors were studied at Chokai Village, Akita Prefecture and Ohasama Town, Iwate Prefecture by using radio opaque markers that were developed by Hinton et al. Gastric cancer mortality rate of Chokai people is very high and it amounts to about 6 times in male and 1.6 times in female than that of Ohasama. Transit times of at least 80% excretion of the pellets were used as indicator of BTT. BTT of Akita, and Iwate people were 34.09±3.30hrs and 43.89±4.27hrs, respectively. In 100% BTT, the difference was greater and it was significant at p<0.05.
Frequency of excretion showed the same trend as BTT, and it required 1.79±0.10 times in Akita and 2.20±0.14 times in Iwate for excretion at least 80% of the pellets. The difference was significant at p<0.05. About 65% of pellets were excreted at the first excretion of Akita people, while it was about 50% in Iwate people. Dispersion of excretion was observed in Iwate. There were no differences in frequency of bowel movement between these two regions, but very wide interindividual differences were observed.
Stool weight per excretion of Akita people was significantly greater than Iwate, and stool weight per day also had the same trend. Significant coefficient correlation between BTT and stool weight was observed only in Akita. Coefficient correlation between stool weight per day and the frequency of excretion in 5 days were significant both in Akita and Iwate, but they were possitive in Akita and negative in Iwate.
BTT has been studied regarding its relation to the colon cancer mortality, but further studies on the relationships of food ecology, BTT and the gastric cancer must be made in the near future.
