 Patients diagnosed with ulcerative colitis UC, a specific type of inflammatory bowel disease, will be invited to take part in this study. The investigators do not know what causes UC. However, the microbes such as bacteria and viruses, which normally live in our intestines are thought to play an important role in the development of UC. There are many treatment options for UC such as steroids,and other medications that decrease inflammation. However, none of these can cure the disease. 