[Age- and sex-specific standard values of colonic transit time in healthy subjects].

Use of radiopaque markers with a plain X-ray of the abdomen is a simple technique to measure mean segmental and total colonic transit time. We evaluated 128 healthy volunteers with a mean age of 40 years (range 20-81 years) from three different parts of Switzerland to assess age and sex specific normal transit times. In men and women colonic transit time was not influenced by age. The mean transit time was significantly shorter in men than in women (30 +/- 2 hours versus 41 +/- 3 hours: p less than 0.05). In men the transit time was also influenced by smoking. Non-smoking men had a significantly shorter transit time than smokers (26 +/- 2 hours versus 40 +/- 5 hours: p less than 0.05). In women, neither smoking nor the menstrual cycle influenced transit time. For normal colonic transit time we recommend up to 66 hours for smoking men, up to 44 hours for non-smoking men and up to 70 hours in general for women.