I'm a lot older than you but I underwent this operation five years ago. In response to another Medhelp patient's question I posted my own experience on Medhelp at:-
http://www.medhelp.org/posts/show/523166
Have a look at this and do come back if you have any questions. You might want to print off a copy of my posting and show it to your surgeon and ask him/her whether you can expect the same (more or less).
regards
Morecambe
Removing the colon is a very common procedure. My eldest son had his removed at 16, my youngest son at 12, and my grandson at 10. The biggest problem are the frequent bowel movements afterwards until your body adjusts. They gave my family anti-diarrhea medication to control theirs. My son is 38 now, and is a marathoner, ultrathoner, speed hiker, and mountain biker. He goes on hikes where he is gone for months at a time. He is very pro-active with his health, and knows what he needs to keep with him on these hikes to keep from getting dehydrated. But there is no stopping him, he lives a very active, normal life, challenging his mind and body at all times. He said having his colon removed was merely a bump in the road, and is thankful to have been given the opportunity to have a life. You'll do great! They have made soooo many advances in this type of surgery since my sons had it. It's okay to be scared, we are all afraid of the unknown, but your life will be better. Your age is a great advantage, I learned this from my boys and grandson. Please keep us posted on how you are doing, and know that we will all be thinking of you. Don't concern yourself with your weight, it will come back so quickly. Just concentrate on healing and getting back into the game of life!
I have had this surgery three times (two colon resections and finally total removal). You will lose a little weight just due to not eating before and after the surgery. You should put it back on fairly quickly after you began to start eating. This operation affects everyone differently. The tough part is adjusting to living without a colon right after the surgery. I had to be close to a bathroom for about 2 months following surgery due to frequent bowel movements. It gets better with time. It's normal to be scared for any surgery but stay strong and say a prayer and things will be fine. They do this type of surgery pretty often now and they should know what they are doing. Ask a lot of questions to your doctors prior and after the surgery so you feel comfortable. The good for you is your age. Being young you will most likely heal quickly and adjust to things much faster than I did. Hope this helped. If you have other questions I will try to answer them and will also keep you in my prayers.