172) Barb has Crohn's disease, a regional inflammation of the intestine. The disease is thought to have some genetic basis, but the actual cause is as yet unknown. When the disease flares up, she experiences abdominal pain, weight loss, and anemia. Which part(s) of the intestine is (are) probably involved, and what is the cause of Barb's symptoms?
The small intestine, especially the jejunum and ileum, is probably involved. Regional inflammation is the cause of Barb's pain. The inflamed tissue will not absorb nutrients; hence, she is losing weight. Among the nutrients that are not absorbed are iron and vitamin B12, which are necessary for formation of hemoglobin and red blood cells; thus, she has developed anemia.