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Updated: Jul 13, 2026

Gastrointestinal Motility Monitor (GIMM)
Published on: December 1, 2010
Gut motility and transit changes in patients receiving long-term methadone maintenance
C S Yuan1, J F Foss, M O'Connor
1Department of Anesthesia and Critical Care, Pritzker School of Medicine, The University of Chicago, Illinois 60637, USA.
Abstract:
This study was conducted to survey gut motility and transit in 19 volunteers receiving methadone maintenance who were opioid-dependent, and to measure the oral-cecal transit time in these individuals using the lactulose hydrogen breath test. None of these patients reported constipation problems before use of illicit drugs. During current long-term methadone therapy, 58% of patients experienced some degree of constipation, and two of these 19 patients reported that constipation was a very serious problem. Mean +/- standard deviation (SD) oral-cecal transit time in these individuals was 159+/-49.2 minutes, which is significantly longer than the transit time recorded in two previous studies of healthy volunteers (P < 0.01). These results indicate that tolerance to opioids does not appear to extend to gastrointestinal motility and transit. It seems that patients receiving long-term methadone therapy are a good model for use in evaluating gastrointestinal effects of opioid antagonists.
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