Rectal varicose vein. Endoscope view of a tortuous and distended varicose vein (varix, down left) in the rectum, the last part of the large intestine. The varix is due to increased blood pressure (hypertension) due to cirrhosis of the liver. Also seen is a spider angioma (red, upper right), a lesion which may bleed, leading to blood in the faeces (melaena). The varix may also rupture, which can also cause melaena. Varices can be treated by sclerotherapy (injection of a chemical to block the veins) or, in severe cases, by the removal of the affected part of the colon.