Sigmoidometry: a method assessing sigmoid colon function

The purpose of this communication is to present a method that assesses the sigmoid colon (SC) volume, pressure and compliance both quantitatively and qualitatively. The response of the SC pressure to SC distension was recorde d in 12 healthy volunteers. The SC was distended by means of a condom, whic h was applied to an 8 F tube and inflated with carbon dioxide at a rate of 150 ml/min. The SC pressure was measured by a saline-perfused 8 F tube and the intra-abdominal pressure by a catheter placed in the urinary bladder. A curve called 'sigmoidometrogram' could be recorded and assessed qualitativ ely and quantitatively. The curve had a 'tone limb' representing the SC pre ssure upon distension and an 'evacuation limb' representing the SC pressure during balloon expulsion. The former showed insignificant pressure elevati on (P > 0.05) with increasing volumes of CO2 inflation. It exhibited minor fluctuations which paralleled those of the intra-abdominal pressure. The 'e vacuation limb' described a curve with an ascending limb continuous with th e tone limb and a descending one, which descended vertically to the base li ne. Quantitatively, the infused CO2 volume and intrasigmoid and intra-abdom inal pressures could be determined from the curve at each of the distension and expulsion sensation. Consequently, the SC compliance could be calculat ed. A normal sigmoidometrogram seems to reflect the normality of the sigmoi d wall structure, afferent axons and central sensory pathways. Alteration o f any of the components of this pathway is expected to change the measureme nts of SC volumes, pressure, compliance and sensation; it would also distur b the morphometry of the curve.