The main symptoms of ulcerative colitis are: recurring diarrhoea, which may contain blood, mucus or pus abdominal pain needing to empty your bowels frequently You may also experience fatigue (extreme tiredness), loss of appetite and weight loss. The severity of the symptoms varies, depending on how much of the rectum and colon is inflamed and how severe the inflammation is. For some people, the condition has a significant impact on their everyday lives.