Relation between gastric emptying and small bowel transit in normal subjects studied with breath tests

Abstract

For gastric emptying (GE) and orocecal transit *C breath tests have been developed. Combining labels allows to measure gastric half emptying time (t l12g) using [J4C]octanoic acid and orocecal transit time (OCTT) using lactose-[I3C]ureide. Applying deconvolution distills the small bowel half emptying time (tI/2sb)from these tests. The aim was to study the relation between gastric emptying and small bowel transit with these techniques. Methods: 65 healthy subjects performed a breath test using a meal of 440 kcal with the above described labels in an omelet. Breath samples for 14C and 13C were obtained before and every 15 minutes after eating the test meal during 4 and 10 hrs respectively. Calculations were done via deconvolution to obtain tl/Zg' Further deconvolution of the percent dose recovery curve (PDR) in breath 13C02 with the PDR curve from breath 14C02 resulted in a curve representing entry of the BC label into the cecum, yielding tll2sb. Results: The median values in min were: t l l Zg: 95; OCTT: 300; tl/Z,b: 438, the P90 being 166, 420 and 743 minutes respectively. Correlation of tll2g and t1l2sb was significant at -0.25. This is illustrated in the figure, with P90 for both. The combination of slow GE with slow small bowel emptying never occurs. Conclusion: The significant negative correlation of t1l2sb and t1l2g is due to the lack of the combination of delay in both. This is an indication for a compensatory effect of small bowel emptying for slow gastric emptying. Rapid gastric emptying is not necessarily compensated by slow intestinal transit.