The colon is one of the organs, the entirety of which is examined best by roentgenology, and barium enema isused extensively for this purpose. it is however not always easy to secure films of satisfactory quality becauseof the difficulty of cleansing the colon thoroughly before examination. In spite of a rigorous preparation, oftenthe remained fecal material and residua of castor oil impose perplexing problem. The present study has beenundertaken to improve the conventional barium enema without employing any special device or medication other thanthose at hand. The clinical materials consisted of 50 cases each of conventional and refined barium enema study performed at the Dep. Radiology St. Mary's Hospital, Catholic Medical College during the period fo 7 months from January 1971. Methods are detailed in Table I. The results, scored according to modified Murray's criteria, were compared each other and following conclusions were drawn. 1. It must be emphasized that thorough final wash-outenema should be performed by a well trained person at the Dep. of Radiology, and use of an antispasmodic agent is encouraged to relieve abdominal discomfort during barium instillation, and further help differentiate functional from organic spasm. 2. Adding of 0.25% tannic acid to barium suspension rather than to cleansing-enema water ismuch more effective in enhancing mucosal coating and barium emptying. Double contrast study by the present methodis as much effective as the Malmo method in disclosing minute lesions of the colon. 3. Shift of the time of castoroil administration from 9 to 6 o'clock in the evening before examination did not result in any significantly earlier termination of rush.