Small bowel neuroendocrine tumours (NET) are relatively rare malignancies. Due to the lack of specificity, the symptoms are usually initially attributed to irritable bowel syndrome. Frequently there is a delay of years after the onset of symptoms, before the diagnosis is made. We describe two patient cases with a small bowel NET that illustrate the typical course of the symptoms, as well as the complications of carcinoid syndrome, carcinoid heart disease, mesenteric venous congestion and arterial ischemia. On coloscopy the primary tumour can often not be reached. CT scan is the best diagnostic modality and should be considered in a patient with abdominal pain, diarrhoea, weight loss and a negative coloscopy, especially in the presence of flushing. In a non-curative situation, first-line treatment consists of a somatostatin analogue, in order to prolong progression-free survival and reduce hormonal hypersecretion. Palliative surgery can also play an important role in the management of small bowel NET.