Operative experiments on laboratory animals and roentgen studies on man have yielded most of the knowledge concerning the muscular activity of the colon. The information obtained with the roentgen rays is limited because only gross changes are revealed. Operative experiments on animals also have some shortcomings due to inability to elicit subjective symptoms or to the abnormal conditions which anesthesia and surgical intervention represent.
This is a study of the movements of the rectum before and after a meal and further shows the symptoms produced by the prolonged presence of a mass in the rectum. A balloon inserted into the lower colon of man through a proctoscope and filled with water has served as a medium for recording movements of the colon. Although the lower bowl was emptied of fecal matter before the experiment started, the results are interpreted as applying to a filled colon because the size and shape
HINES LE, LUETH HC, IVY AC. MOTILITY OF THE RECTUM IN NORMAL AND IN CONSTIPATED SUBJECTS. Arch Intern Med (Chic). 1929;44(1):147–152. doi:10.1001/archinte.1929.00140010150012