A case of vascular malformations of the small intestine associated with malrotation Type I of the right colon is reported. Representing rare conditions, vascular malformations in the small bowel are not accessible endoscopically. Therefore, gastrointestinal haemorrhage originating from this "terra incognita" is difficult to diagnose. Our patient had a medical history of anaemia of 17 years before admitted to our hospital. After a preoperative blood pool scan had evidenced the bleeding source in the proximal jejunum, the patient underwent explorative laparotomy. The bleeding source was identified and resection of a jejunal segment was performed. Intraoperatively, malrotation type I was found. Histological examination revealed angiodysplasia extending full thickness of the intestinal wall with predominance in the submucosa and serosa. Secondary arterialisation was seen in the vessels of the serosa resembling varicosis-like lesions at gross inspection. The patient did not suffer from portal hypertension. Postoperative course was uneventful and no further bleeding occurred.
