Bowel and colon cancer are really unlikely. Those are the same (the bowel is the colon) and it's a really slow growing cancer and you are not the right demographic for it. Your age makes it unlikely. But since you suspect it, then talk to your doctor. You can do a colonoscopy. They have a new test that is pretty awesome and less invasive. My doctor calls it poop in a box. You get a kit and it fits into your toilet, you do your business, pull out the kit, add a solution, seal it and mail it off. They test it and it has a 95% accuracy rating. You may have irritable bowel syndrome though or something else going on. A gastroenterologist will be able to help you. good luck