Digestive System Diseases like Ulcerative Colitis affect the digestive system and can cause symptoms such as stomach pain, diarrhoea and tiredness. Ulcerative Colitis is a long-term condition but with the right treatment and support, many people can manage it well and enjoy everyday life. This section explains more about Ulcerative Colitis, what causes it and how it can be treated — so you can feel more informed and confident with managing your health.