In vitro studies have shown that estrogen and progesterone can affect the contractile response and myoelectric activity of the gastrointestinal smooth muscle. The present study was designed to investigate the effect of sex steroid hormones on gastric emptying and gastrointestinal transit were assessed in rats 15 min after intragastric instillation of a test meal containing charcoal and 51Cr. Gastric emptying was determined by measuring the amount of labeled chromium contained in the small intestine as a percentage of the initial amount received. Gastrointestinal transit was evaluated by calculating both the geometric center of distribution of the radiolabeled marker and the charcoal transit in the intestine. The experimental animals included diestrus rats; ovariectomized rats treated with vehicle, estradiol, and/or progesterone; and normal male and orchiectomized rats treated with vehicle or testosterone. Female rats in diestrus had a slower gastric emptying and a lesser geometric center value than ovariectomized rats. Estradiol inhibited gastric emptying but did not affect gastrointestinal transit. Progesterone increased gastric emptying. Progesterone at lower dose (10 mg/kg) decreased the geometric center compared with higher doses (20 or 40 mg/kg) or vehicle controls. A mixture of estradiol (10 micrograms/kg) and progesterone (20 mg/kg) inhibited gastric emptying to a similar degree as estradiol (10 micrograms/kg) did. Testosterone had no influence on gastric emptying or gastrointestinal transit. These results suggest that estradiol and a mixture of estradiol and progesterone inhibit, whereas progesterone enhances, gastric emptying. Testosterone did not play a role in gastrointestinal motility.

Irritable bowel syndrome (IBS) has been one of the commonly presented gastrointestinal disorders. It is of interest how commonly it presents in the society. Western studies indicated that most population-based IBS prevalences range 10%-15%. It is believed that IBS is prevalent in both East and West countries without a significant prevalence difference. Most recently, the Asia IBS prevalence has a higher trend in the affluent cities compared to South Asia. Since many Asia IBS prevalence studies have been published in the recent decade, we could compare the IBS prevalence data divided by various criteria in looking whether they were also comparable to this of West community. Summarized together, most Asia community IBS prevalences based on various criteria are usually within the range 1%-10% and are apparently lower than these of selected populations. Within the same population, the prevalence orders are first higher based on Manning criteria, then followed by Rome I criteria and finally reported in Rome II criteria. Overall, the median value of Asia IBS prevalences defined by various criteria ranges 6.5%-10.1%. With regard to gender difference, female predominance is usually found but not uniquely existed. For the IBS subtypes, the proportions of diarrhea predominant-IBS distribute widely from 0.8% to 74.0%, while constipation predominant-IBS proportion ranges 12%-77%. In conclusions, current Asia IBS prevalence is at least equal to the Western countries. Female predominant prevalence in Asia is common but not uniquely existed, while the proportions of IBS subtypes are too variable to find a rule.

The prevalence of reflux esophagitis in Taiwanese is 12% and most are mild grade and free from reflux symptoms. Hiatus hernia, male sex, and chronic obstructive pulmonary disease are 3 independent risk factors for development of reflux esophagitis. H. pylori infection did not protect subjects from reflux esophagitis.

The 13C-UBT performed with infrared spectrometry is a highly sensitive, specific, and non-invasive method for the detection of H. pylori infection. The immediate availability of the test result and technical simplicity make it particularly effective in routine clinical practice.