THE CLINICAL-VALUE OF SOLID MARKER TRANSIT STUDIES IN CHILDHOOD CONSTIPATION AND SOILING

Assessment of constipation in childhood is difficult, particularly whe n the presenting symptom is spurious diarrhoea or faecal incontinence. We have therefore assessed the clinical usefulness, reliability and a cceptibility of a solid marker transit technique in 52 patients with c onstipation (median age 8.0 years; range 2-13.5 years) at two referral centres. Median duration of symptoms was 60 months. Soiling was a pro minent feature in 43 children (83%). Ten, 3 mm pieces of 6FG radio-opa que Silastic tubing were given orally at 9am on days 1, 2 and 3 and a plain abdominal film taken on day 5. Laxative treatment was not interr upted. Each film was divided into right colon, left colon and rectosig moid areas, using bony landmarks, and the marker content of each area counted. The coefficient of variation of intra and inter-observer erro rs was 3.1% and 2.1% respectively. By day 5, 7% (group median) of mark ers were still in the right colon, 17% in the left colon and 42% in th e rectosigmoid. Twenty-one patients(40%) had normal transit, 4 (8%) mi ld delay, 9 (17%) moderate and 18 (35%) severe transit delay. Marker d istribution indicated slow pancolonic transit in 29% and slow segmenta l transit in 10%. In 21%, clustering of markers in the rectosigmoid su ggested outlet obstruction. A significant correlation was found betwee n bath transit delay and marker distribution and the severity of clini cal symptoms of constipation and soiling. Repeat studies in six childr en following colonic evacuation revealed significant improvement (P< 0 .05) in marker transit. The test was well tolerated and was useful in establishing the diagnosis of constipation in children with soiling or spurious diarrhoea and in assessment of its severity and its response to treatment.