 The investigators believe that sickle cell patients who develop frequent painful crisis may have a different pattern of bacteria in their intestine when compared to those whose painful crisis occurs infrequently. In this study, the investigators propose to study sickle cell subjects blood to determine how many activated white blood cells heshe have. The investigators will also examine hisher stool to compare the bacteria in hisher stool to those other sickle cell patients. The investigators will then investigate whether or not the results from the blood and stool tests correlate with how frequently the patient develops painful crisis. 