Manometric studies were performed to evaluate motor activity of several types of esophageal substitutes: total stomach (5 patients), isoperistaltic gastric tube (5 patients), jejunal Roux-en-Y loops (4 patients), and isoperistaltic left colon (15 patients). Motor behavior of substitutes was assessed following dry swallows and following several stimuli: intraluminar injection of 30 ml of water or 0.1N hydrochloric acid and swallowing pills. Following dry swallows, there was no response with either stomach or isoperistaltic gastric tube, jejunum showed a variable response, and a response was infrequent in patients with colon transplants. After dry swallows, transmission of the pressure wave through the anastomosis was not observed in any patient. Total stomach and isoperistaltic gastric tube did not respond to any stimulus. Jejunum responded with progressive waves after water and solid stimuli, and had a hyperkinetic response after acid injection. Colon had a constant (80 to 90%) and homogeneous response with progressive waves after all stimuli. After wet swallows, there was transmission through the anastomosis in 2 patients with colon transplants. Our data indicate that stomach and isoperistaltic gastric tubes do not contribute actively to the onward transmission of food in the digestive tract. Jejunum may contribute actively in digestive transit, but its responses are variable. Having steady and homogeneous responses, colon segments take an active part in transit.