We present a case of lower gastrointestinal bleeding (LGIB) in a patient with previously diagnosed aortic dissection extending to the superior mesenteric artery (SMA). Ischaemic gut due to thrombosis of SMA was considered. However, exploratory laparotomy carried out revealed healthy gut with bleeding jejunal diverticula, excision of which relieved the symptoms. Jejunal diverticula, although rare, must be considered among all the possible causes of LGIB.