This natural history protocol provides for the evaluation of patients with idiopathic inflammatory bowel diseases (ulcerative colitis, Crohn's disease, IBD associated with immunodeficiency and genetic diseases such as chronic granulomatous disease and Hermansky-Pudlak syndrome, and additional undefined inflammatory conditions of the gut) either on an inpatient or outpatient basis. The purpose of this protocol is to assess the extent and activity of the disease in such patients, conduct immunologic studies of lymphocyte and antigen-presenting cells derived from peripheral blood and tissues, administer and monitor treatments, and study the genetic risk factors for these diseases. This study will also be used to provide a mechanism for procurement of intestinal samples obtained at sites outside the NIH at the time of medically indicated surgical or endoscopic procedures from patients with IBD. In addition, it will allow for the procurement (send-in) of blood for both immunological studies as well as DNA preparation as more IBD susceptibility genes are discovered and we further our work on association of genetic polymorphisms/mutations with the phenotype and immune abnormalities observed in our IBD patients. This protocol will also allow for the procurement of blood and tissue samples from healthy volunteers (without IBD) here at the NIH to use as a control group in comparison to the immunologic and genetic data we obtain from the IBD patients that are enrolled. The immediate aims of these studies are to define the immunologic abnormalities present and to identify genetic susceptibility factors in patients with these diseases. The long-term goal of this protocol is to identify specific targets for development of novel therapeutics for inflammatory bowel diseases.