Chronic diarrhoeal illnesses with nausea and weight loss are a common indication for gastroenterology review. While many such cases have intra-luminal aetiologies, such as inflammatory bowel disease, coeliac disease or other malabsorptive conditions, with many other cases due to functional gut disorders or systemic malignancy, clinicians must also keep vascular disorders in mind. Here we report a patient with a delayed diagnosis of chronic mesenteric ischaemia after 6 months of gastrointestinal symptoms strongly mimicking an alternative diagnosis such as inflammatory bowel disease due an atypical predominance of nausea and diarrhoea rather than pain. We briefly review the literature on treatment of this condition but also discuss with particular attention the sequence of cognitive errors made by clinicians that led to a diagnostic delay, inviting readers to thus reflect on how such errors can be minimised in their practice.