The association of bowel preparation quality with the PC interval and intervention using SMS. Ottawa Rt is Ottawa score of the right colon (cecum, ascending colon). Ottawa mid is Ottawa score of the midcolon (transverse, descending colon). Ottawa Lt is Ottawa score of the left colon (the rectosigmoid colon). Ottawa fluid is the fluid quantity of the entire colon. PC interval, preparation-to-colonoscopy interval; SMS, short message service of cellular phone.