the presence of the cancer
Colorectal cancer can grow for years before causing any symptoms. Knowing what to look out for can't hurt. The presence of a tumor in your bowel throws things off. As your body tries to adjust to its presence, demands, and byproducts, you may experience changes in your bathroom habits. For example, let's say a tumor is slowly growing in your colon, inhibiting the flow of solid waste. You may or may not notice that you're defecating less often. But if the tumor gets large enough, it may become very difficult for your poop to get by it and you'll end up constipated. Sound like a crap shoot? (No pun intended.) The tumor may obstruct your bowel. You may notice a difference. You may get constipated. That's why, in general, it's best to get regular screenings rather than rely on symptoms to alert you to the presence of the cancer. Imagine a three-lane tunnel full of cars, all driving through with a nice, steady flow. Now imagine that two big rigs decide to block the left lanes in tandem... then they slow to a stop. Both of them. Blocking both left lanes. What do the cars do? They start filing to the right so they can get around the obstruction. The same sort of thing happens in the bowel. Everything is flowing fine and dandy until a tumor starts to grow, causing an obstruction. As the obstruction gets bigger, the space around it gets smaller. So, as you might expect, tumors toward the "tunnel exit" tend to cause this effect of narrowed stool. Bloating may be the result of a bowel obstruction. Cramping may be caused by constipation or diarrhea. In more advanced stages of colorectal cancer, severe abdominal cramping may be caused by the tumor perforating (poking through) the bowel wall. Tumors tend to bleed. Not a whole lot and not constantly, but they do bleed. As a result, some of that blood may be found in your stool. If the tumor is in the right colon, the blood will most likely be dried and virtually invisible by the time the poop leaves the body. However, if the tumor is in the rectum or toward the end of the left colon, it may still be fresh and therefore, bright red. Many of us wouldn't want to question unexplained weight loss. We'd just be happy to be losing weight! But, even though the prospect of losing weight without even trying may seem a blessing, it really is something to question. It's the old "if it sounds too good to be true..." idea. The reason is that weight loss that comes out of nowhere is generally a sign that something is wrong with the body. In the case of colorectal cancer, unexplained weight loss is an indication that a tumor is blocking the bowel somewhere along the line. If you work ten hours a day and sleep two, it's little wonder why you're exhausted. But if you're caught up on your sleep and still feel tired, there may be another force at work. One possibility is anemia, a condition where, basically, your red blood cells aren't hacking it for some reason. They're not carrying enough oxygen to your cells like they're supposed to. As a result, you feel tired. Anemia can be caused by insufficient iron in the diet, but also by tumors.