- One of the main and sometimes more obvious warning signs of colon cancer involves a change in bowel movements, both in frequency and consistency. This particular warning sign may manifest as bouts of either constipation or diarrhea. It may also show up as fairly thin or loose stool, or even as the sensation of not emptying the bowels while going to the bathroom.
- Another common warning sign is rectal bleeding. This would include blood in the stool (which may actually appear as the stool being the color of tar) or the presence of blood from the rectum.
- Some people suffering from colon cancer may also experience abdominal pain. This may present itself at the time of a bowel movement, or prior to a bowel movement. It may not be related to a bowel movement but exhibited as cramps or gas.
- As with most forms of cancer, a person suffering from colon cancer may begin to experience a certain amount of fatigue. This could be due to blood loss as seen in rectal bleeding or the tumor itself basically burning calories usually used for energy.
- Another common warning sign associated with many forms of cancer is sudden weight loss. This may be a result of a decreased appetite, the tumor burning calories used to maintain a person's weight and energy or a combination of both.
- Not surprisingly, many people suffering from colon cancer also experience a certain sense of nausea. This may or may not be accompanied by vomiting.
