Age - Usually affect people before the age of 30, but it can occur at later age also.
Cultural Background/Race - it can occur in any race but whites have highest risk. Incidence of Ulcerative colitis is much higher in Ashkenazi jews.
Family history - People having relative such as a parent, sibling or child, with the disease are at higher risk of developing it.
Diet - Since colon is exposed to many dietary substances, these may promote inflammation. These dietary factors have been thought to play a role in the pathology of ulcerative colitis. Excess intake of unsaturated fat, meat protein, alcohol and milk may enhance risk of ulcerative colitis.
Drugs - Around 1/3rd of patients having aggravation of ulcerative colitis reported recent use of non-steroidal anti-inflammatory drugs (NSAID). NSAID use is higher in patients with ulcerative colitis. Also oral contraceptives and antibiotics may slightly increase chance of developing ulcerative colitis.
Stress - Stress factors like psychological and psychosocial stress can exacerbate ulcerative colitis.