The article brings the review of frequent and rare causes of massive bleeding from the lower GI tract and possible therapies. The most frequent causes of massive bleeding from the lower GI tract is diverticulosis of the large intestine, angiodysplasia of the large and small intestines and ischaemic colitis. Rare causes of massive bleeding include inner haemorrhoids and colorectal carcinoma. Fortunately, about 75 % of all cases of massive bleeding from the lower GI tract spontaneously diminish. Treatment of progressive or recurrent bleeding comprises circulatory resuscitation, blood loss supply and administration of haemostyptics. Endoscopic investigation is fundamental (coloscopy, gastroscopy and enteroscopy), which helps to localize the source of bleeding, evaluation and treat the source of bleeding. In recurrent and progressive bleeding angiographic investigation and selective perfusion by vasoconstrictive substance and/or embolisation is preferred. Surgical treatment is needed for patients with acute massive bleeding and those in which the previous treatment failed. Close cooperation of intensive medicine, gastroenterology, surgery and invasive radiology is needed in treatment of severe cases.