Quick Way to Clean Colon? Using fleet enemas now

Hi i'm an 18 year old male and have bowel troubles since i was age 10. In the early days i would only have a bowel movement about once per week and it would take 10+ hours for me to finish only to go once again with diarrhea after i ate many times.

At age 14 i discovered fleet enemas. While they helped a bit they really didn't do much. Now at 18 on a daily bases i use 1-3 enemas and refill them with water and rinse and repeat until my colon is clean. I also only eat once per day (high fiber cereal for the most part) i don't eat i get out of the restroom and my colon is clean. The problem is this process takes me 4-20 hours daily to complete. But i have lots of bowel problems that doctors weren't able to cure after several years so about a year and a half ago i just stuck with the enema's but due to the time it consumes and fatigue this causes me i am unable to live a normal life.

My question is is there a quick convenient way to clean my colon daily, food that would help. ect? I usually either have bad constipation or bad diarrhea or a mixture of both. Any help on this would be eternally appreciated as be able to go quickly everyday would give me a new lease on life.