Diverticulosis of the Small Intestine and Megaloblastic Anemia

Megaloblastic anemia and small intestinal diverticulosis in a 79‐year‐old woman are reported. Laboratory studies showed normal secretion of intrinsic factor and that the anemia was due to defective absorption of vitamin B 12 . The bacterial concentration in duodenal fluid was 3,400,000 E. coli per ml. In vitro the bacteria had a high uptake of “free” 57 CoB 12 and a low uptake of 57 Co bound to intrinsic factor. This supports the theory that small intestine bacteria cause vitamin B 12 malabsorption by inhibitory action on the absorptive epithelium.