A 16-year-old girl being treated for a relapse of promyelocytic leukaemia developed typhlitis of the caecum and ascending colon related to Klebsiella septicaemia during the neutropenic phase, 2 weeks after the start of induction treatment with chemotherapy. After 10 days of treatment with parenteral feeding and antibiotics, massive rectal blood loss occurred, causing haemodynamic instability. Contrast-enhanced abdominal CT showed contrast extravasation in the caecal lumen. This life-threatening situation prompted visceral angiography, which confirmed a contrast blush in the caecum. Subsequent embolisation resulted in haemodynamic stability.