Background: Ambulatory manometric evaluation of the small bowel is a research technique that is approaching clinical applicability, but widespread use has been limited by problems with both tube placement and interpretation. We describe our technique for tube placement and experience using this technique. Methods: Patients presented after an overnight fast. Intravenous sedation was administered (midazolam). Narcotics were avoided due to concerns about alteration of motility. The motility catheter (Konigsberg Instruments, Pasadena, CA) was a 4.7 mm solid state probe with 4 sensors located at 3, 10, 23, and 33 cm from the tip. Special collars 1, 18, and 35 cm from the tip were used to tie short (1.5 cm) lengths of silk suture to the catheter. The motility catheter was lubricated and passed transnasally into the stomach (confirmed fluoroscopically). The patient was then orally intubated with a standard or pediatric endoscope. Using a biopsy forceps without teeth (Bard Forceps Precisor Hot Bx Forceps #852)the suture nearest the tip was grasped and advanced through the pylorus and into the 2nd-3rd portion of the duodenum. The endoscope was then carefully withdrawn and the procedure was repeated for the remaining sutures. The tip of the probe was confirmed to be distal to the ligament of Treitz fluoroscopically and the endoscope was carefully withdrawn with the tube position monitored continuously. The catheter was connected to the recording device (Synetics Medical μ Digitrapper 4Mb), the patient was monitored in the recovery area for at least one hour. The subjects were instructed to eat their regular meals, avoid snacks and keep a detailed diary. They returned 24 hours later, the catheter position was confirmed using fluoroscopy and then removed. The data were then downloaded for analysis. Results: A total of 79 studies were attempted. In 70 of 79 studies (88.6%) the tube placement was successful and the patient was able to undergo the study. The reasons for the 9 unsuccessful tube placements were; inability to achieve adequate sedation for tube placement (2), inability to place the tube due to anatomical factors (5) and emesis of the tube in the recovery area after successful placement (2). There were no complications from the tube placement or endoscopy. Conclusion: Placement of ambulatory motility catheters using this technique is highly successful and acceptable to patients. Radiation exposure is minimized as fluoroscopy is used intermittently. Background: Ambulatory manometric evaluation of the small bowel is a research technique that is approaching clinical applicability, but widespread use has been limited by problems with both tube placement and interpretation. We describe our technique for tube placement and experience using this technique. Methods: Patients presented after an overnight fast. Intravenous sedation was administered (midazolam). Narcotics were avoided due to concerns about alteration of motility. The motility catheter (Konigsberg Instruments, Pasadena, CA) was a 4.7 mm solid state probe with 4 sensors located at 3, 10, 23, and 33 cm from the tip. Special collars 1, 18, and 35 cm from the tip were used to tie short (1.5 cm) lengths of silk suture to the catheter. The motility catheter was lubricated and passed transnasally into the stomach (confirmed fluoroscopically). The patient was then orally intubated with a standard or pediatric endoscope. Using a biopsy forceps without teeth (Bard Forceps Precisor Hot Bx Forceps #852)the suture nearest the tip was grasped and advanced through the pylorus and into the 2nd-3rd portion of the duodenum. The endoscope was then carefully withdrawn and the procedure was repeated for the remaining sutures. The tip of the probe was confirmed to be distal to the ligament of Treitz fluoroscopically and the endoscope was carefully withdrawn with the tube position monitored continuously. The catheter was connected to the recording device (Synetics Medical μ Digitrapper 4Mb), the patient was monitored in the recovery area for at least one hour. The subjects were instructed to eat their regular meals, avoid snacks and keep a detailed diary. They returned 24 hours later, the catheter position was confirmed using fluoroscopy and then removed. The data were then downloaded for analysis. Results: A total of 79 studies were attempted. In 70 of 79 studies (88.6%) the tube placement was successful and the patient was able to undergo the study. The reasons for the 9 unsuccessful tube placements were; inability to achieve adequate sedation for tube placement (2), inability to place the tube due to anatomical factors (5) and emesis of the tube in the recovery area after successful placement (2). There were no complications from the tube placement or endoscopy. Conclusion: Placement of ambulatory motility catheters using this technique is highly successful and acceptable to patients. Radiation exposure is minimized as fluoroscopy is used intermittently.