Colon Motility in Opiate Addiction and Naloxone‐Precipitated Withdrawal

More than half of those who use opiates suffer from constipation, and withdrawal from opiates produces abdominal cramps and diarrhea in 70% to 85%. These withdrawal symptoms may influence the number of opioid‐dependent patients who attempt abstinence and the number who relapse. To characterize the motility correlates of these gastrointestinal symptoms of withdrawal, six patients from a drug treatment program were studied while on maintenance doses of methadone (average of 57.5 mg/d) and during acute naloxone‐precipitated withdrawal. Motility was recorded via open‐tipped catheters at 30 cm and 15 cm from the anal verge during a 15‐minute baseline period and for 15 minutes during mechanical distention of the rectosigmoid colon with a balloon. This sequence was repeated during withdrawal. Subjective symptoms and objective signs of withdrawal assessed at 15‐minute intervals showed that all six patients experienced withdrawal. Sigmoid and rectal motility were also assessed in 18 opiate‐free control subjects. Long‐term methadone use was associated with normal sigmoid and rectal motility under baseline conditions, but methadone users did not show the inhibition in sigmoid motility that normal subjects exhibited following baloon distention. When withdrawal was precipitated by naloxone, methadone users showed significant increases in rectosigmoid motility in association with signs and symptoms of withdrawal.