Gastrointestinal transit in health and disease

Abstract

The uptake of nutrients occurs mainly in the small bowel. However, the time nutrients and other contents spend in the small bowel, i.e. the small bowel transit time is widely uncharacterised in man. Available methods for studying small bowel transit are expensive, time consuming and have limited accessibility. The aim was to develop a practical method for studying small bowel transit as well as gastric emptying and colonic transit in one day. The second aim was to characterise gastrointestinal transit in health and in some common gastrointestinal diseases. The method was based on the use of radiopaque spheres in a test meal to measure gastric emptying and small bowel transit. The spheres were followed using fluoroscopy. Colonic transit was based on ten radiopaque rings given daily for six days with fluoroscopy on day seven, i.e. the measurement day. Detailed gastrointestinal transit parameters were obtained in a large number of healthy subjects as well as in patients with celiac disease before and after treatment and in patients with liver disease and portal hypertension. In addition, patients with idiopathic bile acid malabsorption were studied prospectively. In total 636 transit measurements in healthy subjects and different patients were performed. This one-day transit measurement procedure was non-invasive, reproducible and inexpensive and it was easy to perform. The radiation exposure during the measurement was 2 mS, which is less than the one-year background radiation in Sweden. In healthy subjects, women had slower transit in all segments of the gut. Overweight healthy women had faster small bowel transit and faster transit through the distal colon compared with lean women. The majority of patients with idiopathic bile acid malabsorption were overweight and had accelerated transit in the small bowel and distal colon compared with healthy subjects. Delayed small bowel transit was observed in male patients with untreated celiac disease and in male patients with liver disease. Body mass index increased and small bowel transit accelerated in the celiac patients after treatment. In women with untreated celiac disease, overweight was associated with faster small bowel transit. In liver disease, Small bowel bacterial overgrowth was associated with delayed small bowel transit. Conclusions: This newly developed transit measurement procedure is a valuable tool for the evaluation of large patient materials with suspected transit abnormalities. Gender influences gut transit in health and may influence transit in disease. The association of overweight with accelerated transit on the one hand and celiac disease and liver disease, i.e. disorders of malnutrition with delayed transit, on the other, indicates that gastrointestinal transit may adapt to varying nutritional status in man.