Background: Gut transit measurements are essential for understanding the pathophysiology of many gastrointestinal disorders. The ideal bowel transit test should be easy to perform, widely accessible, reproducible, non-invasive and inexpensive and the risks should be minimal. These requirements prompted us to develop a procedure for simultaneous measurement of gastric emptying, small-bowel transit and colonic transit at one visit. We assessed the influence of gender, body mass index, age, menopause and smoking on gastrointestinal transit in healthy subjects. Methods: Eighty-three healthy subjects (43 women) were included. Colonic transit was based on 10 radiopaque rings given daily for 6 days with fluoroscopy on day 7. Then, the subjects had a test meal containing 20 radiopaque markers. Using fluoroscopy, gastric emptying and small-bowel transit of the markers were followed until they reached the colon. Results: Gastric emptying, small-bowel transit and colonic transit were significantly slower in female healthy subjects compared to males (2.9 (1.6-4.9) h, median and percentile 10-90, versus 2.4 (0.7-3.7) h, P = 0.005; 4.4 (2.1-11.1) h versus 3.2 (1.5-6.0) h, P = 0.00l; 1.5 (1.0-3.7) days versus 1.3 (0.8-1.9) days P = 0.002), respectively. Small-bowel transit was significantly faster in women with overweight and in postmenopausal women compared to lean and premenopausal women, respectively. Conclusion: This procedure meets most of the requirements of the ideal bowel transit test and is easily performed at one visit. Small-bowel transit as well as gastric emptying and colonic transit were significantly slower for women.