Fat absorption in persistent diarrhoea using C-13-labelled trioctanoin breath test

A study was undertaken to investigate intestinal fat absorption in young ch ildren suffering from persistent diarrhoea in comparison with normal: child ren of similar age. Absorption studies were performed using the breath test technique. Following oral administration of labelled triglyceride ([C-13]t rioctanoin), interval breath sampling was done for 6 h. The time course of excretion of (CO2)-C-13 in the breath was determined by isotope ratio mass spectrometric analysis of the gas samples. Excretion curves were constructe d from the mean values of (CO2)-C-13 dose (per cent) excreted at each time point in breath samples and areas under the curve were determined for diarr hoea cases as well as for normal subjects. The time course of (CO2)-C-13 ex cretions and areas under the curve thus obtained were compared with each ot her and also with a reference study in which data from known malabsorption cases were available. The time of peak (CO2)-C-13 excretion in diarrhoea ca ses ranged from 60 to 240 min (average 150 min) compared with 120 to 270 mi n (average 195 min) for normal subjects, the level of peak of (CO2)-C-13 ex creted/h was 4.8 +/- 1.2 per cent in diarrhoea cases and 5.3 +/- 2.3 per ce nt in normal children (NS). Mean areas under the carve for the two groups w ere 18.9 +/- 3.4 per cent for normal and 17.6 +/- 4.1 per cent dose (CO2)-C -13 excreted/6 h for diarrhoea cases (NS). These results indicate that inte stinal absorption of medium chain triglycerides was not impaired significan tly in the cases of persistent diarrhoea studied.