Follow-up:


What possible nutritional complications might occur in a patient who undergoes a near total ileal resection, 
with loss of the ileocecal valve?

1. Megaloblastic anemia may occur, because of the patient’s likely inadequate absorption of Intrinsic 
factor-bound vitamin B12, which is normally absorbed in the ileum.  Because we have a large storage 
capacity for Vitamin B12 and minimal obligatory loss, it will take a long time before overt deficiency 
develops- However, I would recommend prophylactic treatment consisting of monthly IM injections of 
1000 micrograms of vitamin B12. 

2. Diarrhea and steatorrhea can occur because of  complex interactions between fatty acid and bile acid 
synthesis and malabsorption.  Following small ileal resections (between 30 and 100 cm), 
malabsorption of bile acids leads to a compensatory increase in hepatic bile acid synthesis, resulting in 
near normal fat absorption with minimal amounts of steatorrhea (8 – 20 g/day).  Because the ileum is 
where bile acids are normally reabsorbed, even small resections of ileum can result in malabsorption of 
bile acids, and the unabsorbed bile acids can irritate the mucosa of the large intestine and produce “bile 
acid diarrhea”.  Although cholestyramine therapy will limit this diarrhea and reduce colonic irritation 
by binding the free bile salts, it may increase steatorrhea by interfering with fat absorption.  Following 
larger ileal resections (greater than 100 cm), the liver is unable to completely compensate for bile acid 
malabsorption and losses.  The total pool of bile acids decreases, and significant fat malabsorption and 
steatorrhea occurs (more than 20 g /day).  Cholestyramine therapy will reduce the quantity of bile salts 
irritating the colon and thereby limit “bile acid diarrhea”, but this will definitely result in greater fat 
malabsorption and steatorrhea.  The dietary restriction  of long-chain triglycerides, with concomitant 
substitution of medium chain triglycerides can permit passive lipid diffusion into enterocytes, 
providing fat calories and minimizing GI fat loss.  Of course, MCT do not provide essential fatty acids, 
but they can provide a source of energy.

3. Kidney stones, or nephrolithiasis, is another potential complication of terminal ileum resection.  It is 
uncommon with smaller ileal resections (less than 50 cm), but would be a distinct possibility in this 
patient.  Oxalate is normally bound to calcium in the colon and eliminated via the stool.  When fat 
malabsorption is present, free fatty acids will preferentially bind to calcium, which makes calcium 
unavailable to bind the oxalate.  Because oxalate is soluble, it is readily absorbed via the colon, leading 
to elevated serum oxalate levels.  The oxalate goes to the kidney, where it binds with calcium, causing 
calcium oxalate stones to form.  Treatment consisting of cholestyramine and a low-oxalate, low-fat diet 
may prevent nephorlithiasis in patients who have undergone large ileal resections. 

4. Cholelithiasis is another potential complication in this patient.  People who undergo large ileal 
resections lose large quantities of bile salts, which decreases the bile salt pool, thereby reducing the 
ratio of lecithin-bile salt to cholesterol, which can lead to stones to form.