Cows with haemorrhagic bowel syndrome were examined by ultrasonography. A 5.0 MHz linear transducer was used to scan the right side of 63 standing, non-sedated cows. The small intestine was found to be dilated and had a diameter of 4.3 to 12.0 cm (mean [sd] 6.76 [1.78] cm), and there was markedly reduced or absent small intestinal motility in all the cows. In 22 (34.9 per cent) cows, empty poststenotic segments of small intestine were seen in addition to empty prestenotic intestine. In 12 (19 per cent) cows, the intestinal lumen contained localised hyperechoic material consistent with blood clots. Fluid with or without fibrin was seen between intestinal loops in 39 (61.9 per cent) cows. Accumulation of ingesta in the abomasum and sometimes in the omasum and rumen was seen in 14 (22.2 per cent) cows. Ultrasonography was considered to be a useful tool for the diagnosis of ileus. However, this imaging modality could be used to make a definitive diagnosis of haemorrhagic bowel syndrome only when a blood clot was seen in the intestinal lumen.