Delayed gastrojejunocolic fistulas in patients previously operated for gastric cancer are often caused by local recurrence of the tumour. We present two cases of delayed gastrojejunocolic fistula without neoplastic recurrence. Both patients had been operated for adenocarcinoma several months earlier; a gastric Billroth 2 resection was performed in both cases. The first patient arrived at our hospital for chest pain, dyspepsia, weight loss, vomiting and diarrhoea. Blood tests showed low levels of vitamin B, proteins and cholesterol. The second patient was admitted for lipothymia, hyporexia, proctorrhagia, diarrhoea and weight loss. Blood tests showed macrocytic anaemia and hypoproteinaemia. The radiological and endoscopic examinations revealed a gastrojejunocolic fistula in both cases. Since gastrojejunocolic fistulas are rarely resolved by conservative treatment, we performed a gastric resection with a histological examination to exclude tumour recurrence in both patients. The aetiopathogenesis of gastrojejunocolic fistulas is unknown. It is conceivable that some agents (such as bile) may damage a mucosa that has been weakened by nutritional deficiency and/or postsurgical microvascular damage. Early and delayed gastrojejunocolic fistulas present the same clinical manifestations, namely, diarrhoea, abdominal pain, weight loss and hypoproteinaemia.