Maximal Histalog test in control subjects and patients with gastrointestinal disease
Raynier, (1792) suggested a direct internal visualization of the healthy stomach with food in it for the most exact physiological understanding. Beaumont (1883) observed the reddening of the gastric mucosa during emotional upsets in his subject, Alexis St. Martin, who had a traumatic gastric fistula caused by a gunshot wound. Cannon (1929) postulated that the emotions of fear and anger were inhibitory to gastric function. Wolff (1947) showed hyperemia of gastric mucosa with increased acidity during aggressive emotional states and pallor and flatness of mucosa with diminished acidity during the emotions of fear and sadness. Brady (1964) showed hypersecretion in his "executive" monkeys during post-avoidance conditioning and hyposecretion in pre-avoidance conditioning. Prout (1824) identified the acid of gastric juice as hydrochloric acid. Pavlov (1902) revolutionized the field of gastric physiology by making surgical pouches and isolating psychological vs. physiological phases of gastric secretion. Even today the study of acid secretion and its regulating components represents one of the most active areas of gastrointestinal investigation. Such terms as "acid stomach" and "heartburn" have become commonplace observations with regards to the production of too much or too little acid by the stomach.