Computerized analysis of gastrointestinal acoustic phenomena (GAP) may offer clinically useful diagnostic information. To explore the utility of rat animal models, we studied GAP in normal and bowel obstructed rats. Methods: A total of 108 one-hour GAP recordings were made in 18 male Sprague-Dawley rats. Initially, normal GAP was analyzed in 3 rats sedated with IM ketamine and xylozine. Inferior vena cava catheters were placed in 16 animals, and threaded dorsally to a silicon harness. The effects of varying IV anesthetic agents (ketamine +/- xylozine, propofol) on bowel sounds was then studied in 4 rats. Finally, a customized “lasso” ligature was placed 2 cm proximal to the terminal ileum in 7 of the last 16 animals. The lasso was left open, with the control wire and sheath exiting dorsally and mounted in the silicon harness. After allowing 4-5 days for postoperative recovery, normal fasted and fed bowel sounds were studied for 1-2 days using continuous ketamine infusions for sedation. The lasso was then tightened to create a small bowel obstruction (SBO) and serial recordings were performed over 1-3 days. The analog signals were amplified, recorded, and digitized. The power spectrum and duration of GAP events were calculated after manually identifying the beginning and end of events. Results: Typical normal GAP in over 63 recordings performed in non-obstructed rats have a very short duration (≈ 3-6 ms). The frequency (“pitch”) of these events is difficult to accurately ascertain given their short duration, but is about 300-600 Hz. In contradistinction, 11 of the 45 recordings performed on the obstructed rats, and none of the 63 recordings in the non-obstructed animals, demonstrated intermittent long duration (≈ 200-1000 ms) and lower frequency (≈ 200-300 Hz) events (p<0.001). Conclusions: 1) GAP can be recorded in rats; 2) SBO animals had significantly different sounds than non-obstructed animals; and 3) Computerized bowel sound analysis may provide a useful modality for diagnosis of bowel obstruction.