Gallium colonic transit study patterns in obstructive defecation

Full text: Idiopathic constipation may be due to delayed colonic transit or ano-rectal dysfunction and obstructive defecation. The aim of this study was to relate patterns of colonic transit to results of ano-rectal manometry. Sixteen patients (4 males, 12 females, age 20-58 years) were studied. All underwent ano-rectal manometric studies and colonic transit studies. The transit studies were performed following the oral ingestion of 4 MBq 67Gacitrate with images performed at 6, 24, 48 and 72 h. Computed data on half clearance times (T1/2), mean activity positions (MAP) and segmental tracer retention were obtained. Five patients had normal ano-rectal manometry, 7 decreased rectal sensation and 4 absent or paradoxical ano-rectal reflex (anismus). The T1/2 for subjects with normal manometry was 78.5 ± 11.9 h, decreased rectal sensation 73 ± 4.9 h and the anismus group 52 ± 12.1 h (P < 0.05). Total retention at 72 h was less at 56 ± 3.73 h in the anismus group compared to normal manometry (74.7 ± 12.2) and decreased rectal sensation (90.7 ± 12.1), with higher MAP and less tracer in the right colon at 48 h in the anismus group (P < 0.05). The results indicate that colonic transit studies in constipated patients with anismus have different patterns to those with normal anorectal manometry or decreased rectal sensation