A recent study published in the Journal de Pediatria assessed clinical features and colonic transit patterns in children with refractory constipation. Here, 79 constipated patients received follow-up care in a tertiary hospital in Brazil. Among these, 28 children were refractory to conventional therapy and underwent a simplified visual method of nuclear colonic transit study, by ingestion of a liquid meal containing 9.25 MBq/kg of (99m)Tc-phytate. Abdominal static images were recorded immediately and at two, six, 24, 30, and 48h after ingestion for qualitative analysis of the radio marker progression through the colon. It was observed that colonic transit had two patterns: slow colonic transit (SCT, n=14) - images at 48h showed a larger part of the tracer remained in proximal and transverse colon, and distal retention (DR, n=14) - after 30h, the radio isotope passed the transverse colon and was retained in the rectosigmoid up to 48h. The SCT and DR group included nine and ten males, respectively - median ages in the nuclear study of 11 and 10 years, respectively, and median durations of constipation of seven and six years, respectively. It was noted that constipation appearing during the first year of age and report of soft stools were more common in SCT patients. While palpable abdominal fecal impaction was found only in DR group. On the other hand, appendicostomy for antegrade continence enema was successful in 30% of the SCT patients. Thus, nuclear transit study distinguished two colonic dysmotility patterns and was useful for guiding refractory patients to specific therapies.