Digestion 0.5% hydrochloric acid (HCl), which lowers the pH to the desired pH of 1-3. Acid release is also triggered by acetylcholine and histamine. The intestinal phase has two parts, the excitatory and the inhibitory. Partially digested food fills the duodenum. This triggers intestinal gastrin to be released. Enterogastric reflex inhibits vagal nuclei, activating sympathetic fibers causing the pyloric sphincter to tighten to prevent more food from entering, and inhibits local reflexes. Protein digestion occurs in the stomach and duodenum in which 3 main enzymes, pepsin secreted by the stomach and trypsin and chymotrypsin secreted by the pancreas, break down food
Stomach disease mucosa which secretes gastric acid is acid-resistant. Gastritis and stomach cancer can be caused by "Helicobacter pylori" infection. There are many types of chronic disorders which affect the stomach. However, since the symptoms are localized to this organ, the typical symptoms of stomach problems include nausea, vomiting, bloating, cramps, diarrhea and pain. Disorders of the stomach are very common and induce a significant amount of morbidity and suffering in the population. Data from hospitals indicate that more than 25% of the population suffers from some type of chronic stomach disorder including abdominal pain and indigestion. These symptoms occur for long