Ulcerative colitis. Endoscope view showing a colon (large intestine) affected by ulcerative colitis. This causes inflammation and ulceration (yellow areas) of the colon lining, leading to abdominal pain and bloody diarrhoea. Severe cases may lead to anaemia due to massive blood loss. Treatment is with anti-inflammatory drugs, but severe cases may require removal of the colon. Chronic colitis increases the chances of developing colon cancer.