There have been articles in the urology literature recently about possibilities of vitamin B-12 deficiency in patients who have had surgery involving the terminal ileum, a portion of bowel that is used in continent urinary reservoir surgery.
Because vitamin B-12 is absorbed exclusively by the distal ileum (the very end of the small intestine), its removal from the gastrointestinal tract makes a deficiency a potential complication.
Vitamin B-12 has two major functions. Essential for normal red blood cell development, it is also necessary for normal nervous system functions. Dietary sources of B-12 are animal products such as liver, milk, and eggs. If the body is not able to absorb the vitamin in the intestinal tract, it must be replaced in injectable form.
If you have a continent urinary reservoir, or other bowel surgery that may have involved removal of the terminal ileum, a yearly blood test can determine your B-12 levels. If a deficiency is detected, monthly injections of the vitamin may be given to maintain adequate levels for the prevention of pernicious anemia.