Inflammatory bowel disease (IBD) refers jointly to Crohn’s disease and ulcerative colitis, two chronic disorders of the digestive tract. With IBD, the primary challenges you can expect to face are digestive ones. But the inflammation may also create problems in other areas. Specifically, the levels of iron in your blood may drop, leading to a condition called anemia, in which your red blood cells don’t get the iron they need to deliver oxygen to your body’s tissues. The most common symptoms of anemia include fatigue and shortness of breath, but extreme cases can lead to serious heart problems. How likely is it that your IBD will cause anemia? Studies report that between 35 and 90% of adults with IBD have low iron levels. What Is IBD? If you have Crohn’s disease, both your small and large intestines are likely inflamed. Unlike Crohn’s, ulcerative colitis involves sores developing on the inside of your large intestine only; your small intestine is spared. Otherwise, the two disorders share enough in common to fall under the same umbrella term—IBD. Both disorders often last a long time with periods of worsening and improving symptoms. And while diet and stress may trigger flares, we still don’t know the underlying cause of both diseases. They also share many of the same symptoms, such as: Abdominal pain Severe diarrhea Bloody stool Reduced appetite Weight loss How can IBD cause anemia? Anemia is characterized by low levels of a natural substance in your body called hemoglobin. Each molecule of hemoglobin is like a delivery truck that carries oxygen through your blood vessels to every corner of your body. Like an actual delivery truck, hemoglobin is partially made of metal—in this case, iron. A shortage of iron means a shortage of hemoglobin. And that means essential shipments of oxygen aren’t arriving on time. The results can include fatigue, chest pain, cold hands and feet, headache, shortness of breath, and dizziness. In severe cases, your heart must work overtime to compensate for the lack of iron. And a stressed heart can start beating irregularly, become enlarged, and even begin to fail. IBD can interfere with hemoglobin’s delivery of oxygen in two ways. For people with IBD, the key problem is that intestinal bleeding sends those hemoglobin delivery trucks on a detour. Hemoglobin no longer travels the familiar passages of your blood vessels. Instead, it exits the circulatory system and travels through your digestive tract. All of the iron that makes up the hemoglobin—along with the precious cargo of oxygen—ends up going the wrong way. You probably know this phenomenon by name: bloody diarrhea. The anemia that results is called iron-deficiency anemia (IDA). Worse yet, the intestinal inflammation of Crohn’s disease can also lower iron levels even earlier in the process. This is the second way IBD can interfere with the delivery of oxygen throughout your body. New shipments of iron arrive in your bloodstream via your diet. When you eat iron-rich foods, the iron is absorbed in your small intestine. But with Crohn’s disease, the small intestine is inflamed. This means the normal pathway iron follows is congested by inflammation—think construction workers blocking off lanes. Given this extra traffic, some of the iron you’re consuming isn’t even making it into your bloodstream. For the delivery trucks, that means iron needed to make hemoglobin isn’t arriving at the hemoglobin factory. This form of anemia is called anemia of chronic inflammation (or anemia of chronic disease). So how can we fix this anemia problem? Well, if your iron levels are severely low, your doctor may advise you to get a blood transfusion. But the easy and preventative measure is to take supplements. Most people with Crohn’s disease won’t be able to absorb oral iron tablets, and the side effects of oral iron tablets might be hard to tolerate. If that’s the case for you, an intravenous (IV) infusion of iron may be the solution. But if you have ulcerative colitis—or if your Crohn’s only affects your colon—then oral iron tablets should do the trick. Talk to your doctor if you’re experiencing symptoms of anemia so you can get your body functioning well again.