A 86 years old man, with past medical history of hypertension, ischemic cardiomyopathy and gallstones, that refused the cholecystectomy a year ago, was seen at the emergency room because dark vomiting and confusion that began two days ago, the physical examination was unremarkable, the blood tests revealed: haemoglobin 12 g/L, 11.350 cells/mm3 leucocytes, protein c reactive 10.58 mg/L (normal value 5 mg/L), normal liver function, 1.9 mg/dL of creatinine and 252 mg/dL of urea. The abdominal X-ray showed some hydroaereus levels in the small bowel. He was admitted in the Internal Medicine ward, a nasogastric tube was placed, intravenous hydration was started and neuroleptics were administrated. At the ward the patient stays hemodynamically stable, without new episodes of vomiting nor confusion and the nasogastric tube drainage was minimum, he was able to drink without any symptoms after 48 h. In the 4th day, his general condition worsened because vomiting and abdominal pain appeared, these symptoms relieved with fasting and antiemetics drugs. An abdominal computerized tomography (CT) scan was performed. What is the diagnosis? The image in the panel A shows a big gallstone, panels B & C show pneumobilia (thin arrow) and the gallstone in the terminal jejunum (thick arrow) (Fig. 1). The gallstone ileus is an infrequent condition, its incidence varies from 0.5 to 4% [[1]Aguilar-espinosa F. Sangrado de tubo digestivo y delirium, retos en el diagnóstico de íleo biliar: reporte de un caso y revisión de bibliografía.Cirugía y Cirujanos. 2017; 299: 2-6Google Scholar], it's caused by a fistula that connects the gallbladder with the gastrointestinal tract. Almost 80% of affected have medical history of gallstones, symptoms are diverse as intermittent intestinal occlusion, vomiting, upper digestive haemorrhage, and diffuse abdominal pain. The Rigler's triad that consists in: gas in the biliary tree, small intestine occlusion and gallstone in the intestinal lumen, is usefull to confirm the diagnosis. This entity is more frequent in patients over 65 years old [[2]Sahsamanis G. Maltezos K. Dimas P. Tassos A. Mouchasiris C. Bowel obstruction and perforation due to a large gallstone. A case report.Int J Surg Case Rep. 2016; 26: 193-196Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar]. The mortality is about 15–30% and depends on the timely diagnosis. The commonest complications are: intestinal occlusion, and perforation due to the gallstone in the gut [1Aguilar-espinosa F. Sangrado de tubo digestivo y delirium, retos en el diagnóstico de íleo biliar: reporte de un caso y revisión de bibliografía.Cirugía y Cirujanos. 2017; 299: 2-6Google Scholar, 2Sahsamanis G. Maltezos K. Dimas P. Tassos A. Mouchasiris C. Bowel obstruction and perforation due to a large gallstone. A case report.Int J Surg Case Rep. 2016; 26: 193-196Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar]. This patient was undergone to laparotomy with enterotomy and gallstone extraction, he recovered well without complication with spontaneous healing of the fistula, as other cases reported [[3]Neary P.M. Dowdall J.F. Evolution of entero-biliary fistula following gallstone ileus management.BMJ Case Rep. 2012; 2012: 1-2Crossref Scopus (3) Google Scholar]. The authors want call attention about this entity that can be misdiagnosed because the unspecific symptoms can lead to major complication, and the Internal Medicine ward physicians must keep in mind this illness in order to do a timely diagnosis.