The Pylorus is a ring like muscle or muscular sphincter the opens and closes to allow the nutrient of the stomach to pass through into the small bowel for absorption. The Pyloric sphincter is located at the lower end of the stomach opening into the duodenum.
When nutrients enter the stomach peristaltic activity (contractions) increases. The chemical composition of food influences the rate of digestion: lipid rich (fatty) meals take longer to digest than carbohydrate meals. The pyloric sphincter holds the food in the stomach until sterilization, conversion and emulsification is complete. The pyloric sphincter does not completely close. It leaves and opening of approximately 3 to 5 cm, just enough to allow fluids to exit out of the stomach.
Control of the sphincter is accomplished by the Vagus nerve and the autonomic and parasympathetic nervous system. These systems cause various hormones to be delivered to the sphincter. Gastrin one of the hormones maintains the tone of the pyloric sphincter and regulates gastric secretion, it also increases peristalsis. Cholecystokinin (CCK) and glucagon inhibit the closure of the sphincter.
Pyloric insufficiency or patulousness of the pyloric sphincter may be caused by one or more of the following factors:
- A genetic defect in the sphincter or in the Vagus nerve control.
- The lack or deficiency of the hormone Gastrin.
- Ulceration of the sphincter.
- Scar tissue on the sphincter from previous ulceration.
When the pyloric sphincter does not close properly, due to any of the above, neutral or alkaline fluids from the duodenum will regurgitate back into the stomach and cause the gastric fluids to quickly become alkaline. Nutrients in the stomach will not get the full benefit of sterilization and conversion, necessary for proper absorption in the small bowel. In many instances the lack of Gastrin will result in esophageal reflux of the gastric fluids, because Gastrin also maintains the tone of the lower esophageal sphincter.
A Heidelberg Diagnostic test will inform the doctor that pyloric insufficiently is present during testing.