Dilatation Or Gastrectasis is usually due to some obstruction, of a chronic character, at the pyloric outlet. Food is retained; this undergoes fermentation and the stomach walls become weaker than ever. This may continue until the organ becomes enormously distended, the mucosa becoming very thin and atrophic. The stomach may be so greatly dilated that the greater curvature will extend not only below the umbilicus, but even down into the pelvis. There may be also a displacement in position, the organ lying almost perpendicularly. Dilatation may also be due to the contraction of adhesions to the outer surface of the stomach.

In some cases, the atonic form, there is a weakening and a relaxation of the walls without any obstruction at the pylorus. In gastrectasis there may be most marked indications of malnutrition.

Acute dilatation, with vomiting of very large quantities of thin fluid, occurs at times shortly after operative procedures of various kinds.

Tuberculosis is extremely rare and syphilitic lesions but little more frequent, although gummata may be found. Sometimes a diffuse cirrhosis of all the gastric coats may be found in syphilitics.

Anthrax, actinomycosis, and glanders have been described.