This study examined the effects of a liquid meal on cholecystokinin (CCK) secretion in patients with severe short bowel syndrome (SSBS) receiving home total parenteral nutrition (TPN) support for 5-19 years after massive small bowel resection. Five patients with SSBS due to superior mesenteric artery or vein thrombosis were included. Five healthy volunteers served as controls. Blood was drawn before and 1 hr following consumption of 250 ml of a liquid diet containing 232 kcal with 8 g fat and 8 g protein. Plasma CCK activity was evaluated by amylase bioassay. All patients had stable weight with a normal BMI and serum albumin level, although there were mild abnormalities in their liver function tests. CCK secretion after stimulation was significantly decreased in patients. These results suggest that reduction in intestinal length influences CCK secretion in response to meal stimulation in SSBS patients.