EVALUATION OF ISOTOPE PROCTOGRAPHY IN CONSTIPATED SUBJECTS

Twelve patients with longstanding constipation were examined by isotop e proctography. Radio-labelled potato mash was inserted rectally to pr ovoke the urge to defaecate and expulsive manoeuvres were recorded usi ng a Gamma-camera. The method illustrated dynamic alterations in the a norectal angles (ARA) which became more acute on 'squeezing', less so on coughing and more obtuse on straining, and maximally so on evacuati on. The pelvic floor (PF) movements were consistently upwards on squee zing, less so on coughing, downwards on straining, and maximally so on evacuation. A useful addition was the measurement of the completeness of evacuation and the time involved. The results were comparable to r adiological videoproctography (P < 0.01), but the isotope method gave greater discrimination for both ARA and PF movement changes. It also a llowed correlations to be made between the pelvic floor descent (P < 0 .05) and anorectal angle changes (P < 0.01) with rectal evacuation.