Abstract
The transit time of carmine through the alimentary canal has been estimated in 65 children with simple chronic constipation but without abdominal pain or faecal incontinence. Comparison was made with matched normal controls and as a result criteria have been suggested which, in conjunction with a complete physical examination, may help to differentiate the normal from the constipated. The carmine test is simple, acceptable, and valid, but though it cannot indicate the type of constipation present it may be useful in estimating its degree. In predominantly rectal constipation there was a significant reduction in severity of constipation in boys over the age of 6 years as compared with girls, possibly due to the supervention of faecal incontinence in boys which excluded them from this series.