Rectal Cancer Signs and Symptoms

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Rectal cancer is included in the term "colorectal cancer" and refers to cancers that are found in the lower portion of the colon near the anus. Being able to recognize the signs and symptoms of rectal cancer is more important than ever following a 2017 study. We've learned that colorectal cancer is increasing significantly in people under the age of 50, and hence people who have not yet reached the age at which colorectal screening is usually performed.

Unfortunately, whether the disease occurs in younger adults or older adults, a delay in the diagnosis of this disease is a problem. The frequent delays result in these cancers being found at more advanced stages of the disease; stages in which the outlook isn't as good. What rectal cancer warning signs should you be familiar with, and when should you contact your doctor? Even though every person is different, let's take a look at the most common symptoms you might encounter.

Signs and Symptoms

The symptoms of rectal cancer are nonspecific, meaning that they could have a number of causes. The chance that a person might have rectal cancer is more likely if more than one of these symptoms are present, but having even one of these signs is a reason to contact your doctor. There are conditions in addition to rectal cancer which can be serious. Let's take a look at the signs and symptoms of rectal cancer everyone should know.

Blood in the Stool

Rectal bleeding (either bright red or dark red in color) is a common symptom of rectal cancer, occurring in 60 to 80 percent of people at the time of diagnosis. This bleeding may be associated with the passage of mucus in the stool as well. The bleeding may not always be apparent, however, and sometimes the bleeding occurs only on a microscopic scale. A test called a fecal occult blood test (FOBT) detects blood in the stool that cannot be seen.

While rectal bleeding is a symptom of rectal cancer, it is also associated with less severe health problems, such as hemorrhoids and anal fissures. There are also some foods, like beets, watermelon, and red licorice that can cause changes in stool color which resemble blood. To be on the safe side, always report any changes in stool color to your doctor.

While bleeding due to rectal cancer usually causes bright red or dark red blood (hematochezia), don't dismiss darker stools. Bleeding higher in the colon, as well as in the stomach often appears black and tarry (melena), or resembles coffee grounds. This symptom can also be a warning sign of serious medical conditions.

Changes in Bowel Habits Such as Diarrhea or Constipation

The second most common symptom of rectal cancer, occurring in nearly 50 percent of people, is a change in bowel habits. This can be diarrhea, constipation, or an increase or decrease in the frequency of bowel movements. With rectal cancer, diarrhea is quite common. The important point with bowel habits is to be alert for a change that represents a change for you personally. Everyone has different bowel habits, and what is normal for one person may not be for another. If you notice any change, talk to your doctor.

Certainly, there are many causes of a change in bowel habits, and your symptoms could be due to something as minor as a change in diet. That said, it's better to be safe than sorry. Talk to your doctor.

Rectal Pressure or Fullness/Sensation of Incomplete Emptying

Another common symptom or rectal cancer is the presence of rectal pressure or fullness, or the sensation that you have to empty your bowel, even if you've just finished. A mass in the rectum can give the sensation of incomplete emptying("tenesmus"), even if you no longer need to pass stool.

Thin Stools

A change in the pattern of a bowel movement to thin- or ribbon-like stools may indicate a problem. A growth in the colon or rectum that is partially obstructing the bowel can change the size and shape of the stool as it exits the body. 

Other conditions may also cause thin stools, such a large benign polyp or hemorrhoids. Some people ask how thin is too thin for stools. While some sources describe thin as "pencil thin" there isn't really a definition. If you notice that your stools are thinner than normal for you, see your doctor.

Abdominal Cramping/Constipation/Bowel Obstruction

When a tumor in the rectum is large, it may obstruct the rectum partially or completely. This can lead to severe constipation and progressively worsening cramping. Small amounts of liquidy stool may be able to pass through the obstruction, but the sensation of constipation will persist. When this occurs, urgent medical care is needed.

Symptoms of Anemia Such as Fatigue

Microscopic bleeding due to rectal cancer often causes anemia. Anemia, in turn, can cause fatigue, shortness of breath (often just with activity at first), weakness, and an elevated heart rate. Fatigue is often the first symptom people note. Most people feel tired at times, but fatigue that is interfering with your ordinary activities could be a symptom of an underlying medical problem. 

Unexplained Weight Loss

Many people welcome unexpected weight loss, but if you're losing weight and haven't changed your diet or exercise, it's important to talk to your doctor. Unintentional weight loss is defined as the loss of 5 percent of body weight over a 6 to 12 month period without trying. An example would be a 200 pound many losing 10 pounds over a 6 month period. Rectal cancer is only one of the possible causes of this symptom, and unexplained weight loss always deserves a visit to your doctor.

Bottom Line on Rectal Cancer Symptoms

Rectal cancer is increasing, with a significant increase in 30 to 39 years olds being noted since 1995 and an increase in 40 to 54 year olds noted since 2005. We don't know the reason. At the same time, the diagnosis of these cancers is often delayed, and consequently, the tumors are often more extensive, making treatment more difficult. Having an awareness of the signs and symptoms of rectal cancer, and seeking attention if you note any of these warning signs, is important in order to detect and treat these cancers as early as possible.

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