Malformation

It may be completely absent, or abnormally small, with atresia or stenosis of the pylorus, or it may be in the form of two pouches connected by a smaller tube (hourglass stomach). The stomach may be reversed in its position in transposition of the viscera.

Circulatory Disturbances

Anemia occurs in cases of general anemia, accompanied, if long continued as in pernicious anemia, by fatty degeneration and atrophy of the mucous membrane. The mucosa is thin and frequently smooth. Active hyperemia is present normally during digestion, and is widespread. If the result of irritation, the color is more intense and is distributed in irregular streaks or patches, particularly on the tops of the rugae. Passive hyperemia is the result of venous stasis in chronic heart and lung diseases and cirrhosis of the liver. The mucosa is purplish in color, swollen, and edematous. Small punctate hemorrhages may occur and also small erosions. The changes are most marked near the pyloric end.

Hemorrhage of varying severity frequently occurs. This may be in the form of multiple, minute areas, or as solitary, large lesions. The punctate form, that is found so repeatedly at post-mortems, is in many cases the result of vomiting during the last moments of life. It may also result from congestion and inflammation, or be met with in various infectious and hemorrhagic diseases. If examined carefully, it can generally be seen that over these hemorrhagic points there is a loss of epithelium. The mucosa not being properly nourished at that point is unable to withstand the action of the gastric juice. Particularly as there is no secretion of alkaline mucus to act as a protection.

Massive hemorrhage occurs in destruction of the mucosa in the course of gastric ulcer and gastric carcinoma. In the peptic ulcer the bleeding usually comes from the erosion of a single blood-vessel and may be so great as to cause death. In hemorrhages from this cause and from traumatism the blood is bright red. In the carcinoma there is a slow oozing from degenerated capillaries, with the "coffee-grounds vomit," blood that has been acted upon by the gastric juices. Melcena neonatorum, vomiting of blood by new-born infants, is accompanied by the formation of ulcers of the gastric mucosa. It apparently results from imperfect respiration, causing a backing up of the blood. By many it is thought to be due to some cerebral lesion.

Thrombosis of the gastric vessels is rare, but is thought by many to be a cause of peptic ulcer and also of the ulcers that are found in the stomach and duodenum in cases of extensive burns. If infectious, abscesses may occur. Embolism is more common; occurs in the course of cardiac disease.