Flow through the sphincter of Oddi was studied by a constant-pressure perfusion 
apparatus, and by using a constant rate of infusion and measuring pressure 
changes just proximal to the sphincter. Pressure changes from balloons placed in 
the gastric antrum and duodenum were recorded. Despite considerable variation in 
activity and behaviour, the following conclusions were reached.1. The sphincter 
of Oddi appears to be partially autonomous but is readily affected by changes in 
duodenal tone.2. Reflex inhibition of the sphincter of Oddi is seen on 
electrical and mechanical stimulation of the gall-bladder but not with passive 
pressure changes within the gall-bladder.3. This reflex is relayed through the 
coeliac ganglion.4. There is a definite relationship between gastric antral 
activity and flow through the sphincter of Oddi. This is more obvious when food 
is present in the stomach.5. Mechanical or electrical stimulation of the 
stomach, duodenum, or upper small bowel influences the tone of the sphincter of 
Oddi.