Longest transit time in GIT is seen in:

C i.e. ColonTransit time in Small Intestine & ColonThe first pa of a test meal reaches the caecum in about 4 hours, all of the undigested poions have entered the colon in 8-9 hours.On average, the first remnants of the meal reach the hepatic flexure in 6 hours, the splenic flexure in 9 hours & the pelvic colon in 12 hours.From the pelvic colon to the anus, transpo in much slowerQ.As much as 25% of the residue of a test meal still be in the rectum in 72 hours.So, the transit time of colon is the longestQ.