Gastric secretory responses to modified sham feeding (MSF) and insulin after vagotomy.

Modified sham feeding (MSF) and insulin tests were carried out in 28 patients after vagotomy. Basal and pentagastrin collections were also performed. Using the secretory data from 9 of the patients with endoscopically proven recurrent ulcer as a reference, 20 gastric secretory indices were studied and critical levels were chosen to provide the maximum sensitivity and specificity. The eleven most discriminating indices were then used to evaluate the remaining 19 patients. There was agreement between the responses to MSF and insulin as to the adequacy of vagotomy in 16 of the patients (84 per cent) and contradictory responses in 3 patients (16 per cent). Overall, MSF responses were as discriminating as the responses to insulin. A simplified ward test, based on crude volume measurements in response to MSF is proposed.