GSTM1 and anemia (phenotype): According to the World Health Organization anemia is defined as a hemoglobin (Hb) level of less than 12.0 g/dl in women and 13.0 g/dl in men.1 Iron deficiency anemia (IDA) has been cited as the most common cause of anemia globally.2 Endoscopies are an effective way for evaluating anemia in the hospital setting.