About Rectal Cancer
Rectal cancer is a disease in which malignant (cancer) cells form in the tissues of the rectum.
The rectum is part of the body’s digestive system. The digestive system takes in nutrients (vitamins, minerals, carbohydrates, fats, proteins, and water) from foods and helps pass waste material out of the body. The digestive system is made up of the esophagus, stomach, and the small and large intestines. The colon (large bowel) is the first part of the large intestine and is about 5 feet long. Together, the rectum and anal canal make up the last part of the large intestine and are 6-8 inches long. The anal canal ends at the anus (the opening of the large intestine to the outside of the body).
Signs of rectal cancer include a change in bowel habits or blood in the stool.
These and other signs and symptoms may be caused by rectal cancer or by other conditions. Check with your doctor if you have any of the following:
- Blood (either bright red or very dark) in the stool.
- A change in bowel habits.
- Feeling that the bowel does not empty completely.
- Stools that are narrower or have a different shape than usual.
- General abdominal discomfort (frequent gas pains, bloating, fullness, or cramps).
- Change in appetite.
- Weight loss for no known reason.
- Feeling very tired.
Health history affects the risk of developing rectal cancer.
Risk factors for colorectal cancer include the following:
- Having a family history of colon or rectal cancer in a first-degree relative (parent, sibling, or child).
- Having a personal history of cancer of the colon, rectum, or ovary.
- Having a personal history of high-risk adenomas (colorectal polyps that are 1 centimeter or larger in size or that have cells that look abnormal under a microscope).
- Having inherited changes in certain genes that increase the risk of familial adenomatous polyposis (FAP) or Lynch syndrome (hereditary nonpolyposis colorectal cancer).
- Having a personal history of chronic ulcerative colitis or Crohn disease for 8 years or more.
- Having three or more alcoholic drinks per day.
- Smoking cigarettes.
- Being black.
- Being obese.
Older age is a main risk factor for most cancers. The chance of getting cancer increases as you get older.