Causes of Iron Deficiency?

I am a 36-year old female with history of asthma, high (controlled) blood pressure, severe IBS and chronic constipation. I developed severe constipation following a female surgery in early 2003 (suspected as bowel adhesions). As a result, I have been placed on a daily combination of laxatives to keep things functional (surgery not recommended). Every day, I take 1/2 capful of Citrucil+1 Tbls of Milk of Mag + 1 capful of Miralax. This has been my regimen since January of 2004. (Earlier trials of Zelnorm and Senekot S were not successful).

In early Janaury, I was diagnosed with iron deficiency. Iron level was orginally 20 with iron saturation of 4. White blood count and hemoglobin were normal. Was put on Slow FE 1x/day to treat the iron deficiency. Now, 12 weeks later, I was retested. Iron levels have not changed much. Iron level is now 22 with saturation of 5. White blood count and hemoglobin were still fine. Have been told to increase my Slow FE to 2x/day. Does anything explain why my iron levels have not significantly improved in 3 months? Normal count should be 35-150 with saturation of 15-55. Could the daily use of laxatives be impacting my absorbtion? I do not experience diarrhea and do not get periods as I take BC pills continuously for endometriosis. Does anything indicate that I may have an iron absorbtion problem and if so, how do they find this out? How long should it take for my iron levels to show improvement? Is there anything else I can do or eat to improve the numbers? Any other health problems that are related to iron deficiency? Any relationship to GI problems? Is there any danger of staying on these laxatives long-term for chronic constipation (IBS specialist says no)? Any advice would be appreciated. Have noticed that complexion has been mildly pale and I have been more tired than usual since low iron.

[Kevin Pho, MD]

Of note, in iron deficiency anemia the iron saturation is typically elevated, not low.  You may also want to consider a serum ferritin which would be a better indicator of iron stores in healthy adults.    You may want to discuss with your personal physician whether the diagnosis of iron deficiency is accurate.

In any case, here are some answers to your questions on iron deficiency.

Most common cause of iron deficiency is blood loss - either obvious or occult.  The GI tract is the major cause for this.

Gastrointestinal malabsorption of iron is a relatively uncommon cause of iron deficiency, although it may be observed in certain diseases associated with generalized malabsorption. An example is celiac disease (sprue), in which there may also be a component of GI bleeding.  

Other causes would be intravascular hemolysis as well as an uncommon condition known as pulmonary hemosiderosis.

If you truly have iron deficiency, I would suggest an upper and lower endoscopy to see if there is a GI source of bleed.  A blood test for celiac disease can also be considered to see if there is evidence of iron malabsorption.

Treatment of iron deficiency with oral therapy should see a rise in blood count in about 3 weeks.

Typically long-term laxative treatment is not the ideal treatment for IBS.  You may want to consider a specific IBS medication such as Zelnorm (for constipation-predominant IBS).  This can be discussed with your personal physician.

Followup with your personal physician is essential.

This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.

Thanks,
Kevin, M.D.

Bibliography:
Schrier.  Causes and diagnosis of anemia due to iron deficiency.  UptoDate, 2004.

[alexandria]

Thank you for your response. Please note, the constipation problem is a result of bowel adhesions from a female surgery, not IBS. Over the past year, I've already had blood work, abdominal xrays, CT scan, upper GI, endoscopy, lower GI, small bowel transit, colon transit study, stomach emtyping study. All were normal. I've also tried 2 trials of Zelnorm, Lactulose, fiber and Senekot. None of this worked. After seeing an IBS specialist, I was advised that the only treatment (aside from surgery which was adamantly rejected)was a combination of laxatives. Is this dangerous?

Considering this history, is a low iron level of 22 with normal blood count unusual? There is no evidence of bleeding,I do not have periods and everything else has come back normal. Anything else to explain the low iron? What should I pursue if oral iron does not work after 3 more months?

[sickm]

A related discussion, what causes lots of red blood cells but all to small to carry oxygin was started.