I am 47 and female. I just found out I have low iron. My heart doctor wants me to see a blood doctor. But I read your article on anemia, which describes how problems with the digestive system can cause low iron. I have had bloating and some stomach pain for a couple of years. Should I see a gastroenterologist?

J.C.

One of the most common causes of anemia is a deficiency of iron. Iron is needed to form the red blood cells that carry oxygen in the blood. Thus, low iron can lead to a low red blood-cell count (anemia), which in turn can deprive the body's vital organs of sufficient oxygen.

There are many causes of low iron levels. The most common is excessive losses from the body. This may occur as a result of heavy menstrual blood losses in young women. In both men and women, the blood loss can also occur from bleeding in the gastrointestinal tract, which may occur so slowly that it is not recognized by the patient. There are many possible causes of gastrointestinal bleeding, including ulcers and tumors.

Another potential cause for low iron levels in the blood is inadequate intake or absorption of dietary iron. Poor intake is very rare, except in patients who are very malnourished, such as alcoholics. Poor iron absorption can occur in people with conditions that affect the lining of the small bowel, such as celiac disease.

Both the age and sex of the patient are important in deciding how best to proceed. In young females who have heavy menses, often no further investigation is done and iron supplements are given to counteract the effect of iron losses. Older women and all men who develop anemia need a diagnostic workup. Tarry, black stools may point to intestinal blood loss as the cause. Stomach pain can indicate the possibility of bleeding (from ulcers, for example), but more specific information would be needed.

So, seeing a gastroenterologist would be an excellent first step in your evaluation. Most often, when iron deficiency is diagnosed, a gastroenterologist performs endoscopic exams to examine both the upper and lower parts of the digestive tract. Further tests and therapy are then guided by the results of these examinations.