When the British surgeon Gilbert Grey Turner for the first time described the abrupt occurrence of blue discoloration (bruising) and induration of the skin in the region of the loins 2–3 days after acute retroperitoneal haemorrhage (the Grey-Turner’s sign) (A), surgery was the only possible way to confirm the diagnosis [1]. The description by Dr. Formagnana [2] also recognizes the importance of this sign today when it plays like a summons for an ultrasound scan, now widely available. The clinical presentation of spontaneous retroperitoneal haemorrhage (SRH) is protean and may be initially vague so diagnosis is often delayed if the clinician is unaware of this condition. The specificity of back pain is low even though it is the most common and earliest symptom, and is especially low in the elderly [3, 4]. Only noticing the bruise in the flank in association with back pain and the important reduction in the Hb levels enabled the physicians to think of a SRH. Unfortunately, the Grey-Turner’s sign usually only appears a few days after the onset of bleeding. What we want to emphasize is that, at the least in the initial stages, there is not any obvious stigmata of underlying retroperitoneal bleeding; so only through a careful integration of history (anticoagulant therapy), clinic presentation (back pain, hypotension, weakness) and laboratory tests (anaemia) is it possible to early on consider the diagnosis. Interestingly, moreover, our patient showed anticoagulation levels within the therapeutic range, normal renal function and platelet count. That is in agreement with the literature available that demonstrates that only roughly one-half or less [3, 4] of patients with SRH show evidence of excessive anticoagulation by blood tests. Taking this into account, anticoagulation levels within a desirable therapeutic range should not lead us to disregard the diagnosis. Our report suggests that due to its pleomorphic presentation SRH could be considered in all patients with back, hip, groin or abdominal pain, anaemia and hypotension, especially if on anticoagulation therapy, when a plausible aetiology is not otherwise found. The history of ischemic colitis was puzzling. Even in the absence of frank rectal bleeding an urgent colonoscopy was indeed performed as the initial diagnostic examination. The sensitivity of lower gastrointestinal bleeding is indeed low (62 %) and although most patients treated supportively recover fully, a minority with severe ischemia may develop sepsis and become critically, sometimes fatally, ill. Another point we want to stress is the usefulness of US as a first-line imaging modality that may guide further investigations. Nowadays the CT scan plays an important role in the diagnosis of SRH, providing useful information on presence, localization, extent, underlying causes and active bleeding (extravasation of contrast material) [5]. Nevertheless US is portable, rapid, non-invasive, irradiation free, hazard free and can be used repeatedly [6]; moreover, thanks to the development of miniaturized ultrasound devices and to the improvement of software we are able to perform it bedside [7]. This is even more important if we consider that delayed diagnosis and inappropriate treatment is associated with high morbidity and mortality; Sunga et al. [3] reported a 30-day mortality of 10 %. In this regard US should be the initial examination G. Carnevale-Maffe First Department of Medicine, Fondazione IRCCS Policlinico San Matteo, University of Pavia, Piazzale Golgi 19, 27100 Pavia, Italy