Identifying Colon Cancer Symptoms

1Pay attention to blood in your stool. If you have ongoing rectal bleeding that doesn’t seem to be a result of hemorrhoids or a tear, it’s a good idea to go to the doctor and get checked out.[1] Blood in the stool is a common symptom of colon cancer.

2Notice changes in your bowel movements. If you are experiencing persistent diarrhea and constipation, that’s something to look into. People with colon cancer may also have long, pencil-shaped stools. The feeling of not being able to completely empty your bowels has also been reported.[2]

Pay attention to patterns you notice with your bowel movements. If things seem to feel different – you experience rectal cramping, you don’t have bowel movements with the same regularity, and your stools look different – make an appointment with your doctor.
These symptoms do not necessarily indicate that you have colon cancer. Similar symptoms are experienced by people with irritable bowel syndrome and a host of other medical ailments.

3Be aware of abdominal pain and bloating. These symptoms go along with the uncomfortable changes you might experience in your bowel movements. If you have pain in your abdominal region as well as bloating that doesn’t seem to have another cause, see your doctor.[3]
Pelvic pain is also experienced by people experiencing the later stages of colon cancer.
Again, these symptoms are shared by many other illnesses, so having them doesn’t necessarily indicate you have colon cancer. Still, it’s a good idea to get them checked out.

4Notice changes in your appetite. People with colon cancer may experience a loss of appetite, along with unexplained weight loss. If you’re losing the desire to eat full meals and don’t enjoy foods you used to eat, colon cancer may be the culprit. Pay attention to changes in your weight, especially if it seems to slide steadily down without effort on your part.

5Determine whether you are uncharacteristically fatigued. This is a common symptoms of many types of cancer, colon cancer included. If you feel deeply tired and weak in conjunction with the other colon cancer symptoms, see your doctor right away.[4]
EditPart 2 of 2: Catching Colon Cancer Early

1Know if you are at risk for colon cancer. Age is the leading factor when it comes to risk, as the majority of people who get colon cancer are over the age of fifty. However, there are several other factors that can play a part.[5] They include:
Being African American. African Americans are at greater risk than other races.
Having a personal history of colon cancer or polyps.
Having an inherited syndrome that can lead to colon cancer, such as familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer (Lynch syndrome).
Leading a sedentary lifestyle. Getting more exercise can help reduce your risk.
Eating a low-fiber, high fat diet. Changing your diet to include more fruits and vegetables and less fat and meat can help reduce your risk.
Having diabetes or obesity can increase your risk.
Smoking and drinking alcohol can increase your risk.

2Get regular screenings. More than 95% of colorectal cancers come from adenocarcinoma polyps. These cancers start in cells that form mucus glands, which lubricate the colon and rectum. Carcinoid tumors, gastrointestinal stromal tumors and lymphomas also cause 5% of colon cancers. The best way to prevent colon cancer is to undergo regular screening tests after the age of 50 to determine whether cancerous or precancerous growths are present. The doctor will perform one or more of the following procedures to determine whether you have colon cancer[6]:
A fecal occult blood test (FOBT), to check for hidden blood in the stools.
A sigmoidoscopy, in which a lighted instrument called a sgmoidoscope is used to check for polyps and growths in the rectum and lower colon.
A colonoscopy, in which a colonoscope is used to examine the entire colon for cancerous or precancerous growths, which are removed and biopsied if found.
A virtual colonoscopy or double contrast barium enema (DCBE), which are different types of x-rays that show polyps and growths on the colon.

Colorectal cancer is a malignant tumor arising from the inner wall of the large intestine.
Colorectal cancer is the third leading cause of cancer in males and fourth in females in the U.S.
Risk factors for colorectal cancer include heredity, colon polyps, and long-standing ulcerative colitis.
Most colorectal cancers develop from polyps. Removal of colon polyps can prevent colorectal cancer.
Colon polyps and early cancer can have no symptoms. Therefore regular screening is important.
Diagnosis of colorectal cancer can be made by barium enema or by colonoscopy with biopsy confirmation of cancer tissue.
Treatment of colorectal cancer depends on the location, size, and extent of cancer spread, as well as the health of the patient.
Surgery is the most common treatment for colorectal cancer.
Chemotherapy can extend life and improve quality of life for those living with colorectal cancer.

What is cancer?

Every day within our bodies, a massive process of destruction and repair occurs. The human body is comprised of about fifteen trillion cells, and every day billions of cells wear out or are destroyed. In most cases, each time a cell is destroyed the body makes a new cell to replace it, trying to make a cell that is a perfect copy of the cell that was destroyed because the replacement cell must be capable of performing the same function as the destroyed cell. During the complex process of replacing cells, many errors occur. Despite remarkably elegant systems in place to prevent errors , the body still makes tens of thousands of mistakes daily while replacing cells either because of random errors or because there are outside pressures placed on the replacement process that promote errors. Most of these mistakes are corrected by additional elegant systems or the mistake leads to the death of the newly made cell, and another normal new cell is produced. Sometimes a mistake is made, however, and is not corrected. Many of the uncorrected mistakes have little effect on health, but if the mistake allows the newly made cell to divide independent of the checks and balances that control normal cell growth, that cell can begin to multiply in an uncontrolled manner. When this happens a tumor (essentially a mass of abnormal cells) can develop.

Tumors fall into two categories; there are benign tumors and malignant (cancerous) tumors. So what is the difference? The answer is that a benign tumor grows only in the tissue from which it arises. Benign tumors sometimes can grow quite large or rapidly and cause severe symptoms, even death, although most do not. For example, a fibroid tumor in a woman’s uterus can cause bleeding or pain, but it will never travel outside the uterus and grow as a new tumor elsewhere. Fibroids, like all benign tumors, lack the capacity to shed cells into the blood and lymphatic system, so they are unable to travel to other places in the body and grow. A cancer, on the other hand, can shed cells that can float like dandelion seeds in the wind through the blood or lymphatic system, landing in tissues distant from the primary tumor and growing into new tumors in these distant tissues. This process of spreading to distant tissues, called metastasis, is the defining characteristic of a cancerous tumor.

Cancer often is referred to as a single entity, but in fact, it is a group of more than 100 different diseases, much like infectious diseases. Cancers are named by the tissues from which the first tumor arises. Hence, a lung cancer that travels to the liver is not a liver cancer but is described as lung cancer metastatic to the liver, and a breast cancer that spreads to the brain is not described as a brain tumor but rather as breast cancer metastatic to the brain. Each cancer is a different disease with different treatment options and varying prognoses (likely outcomes). In fact, each individual with cancer has a unique disease, and the relative success or lack thereof of treatment among patients with the same diagnosis may be very different. As a result, it is important to treat each person with a diagnosis of cancer as an individual regardless of the type of cancer.
What is cancer of the colon and rectum?

Picture of colon (colorectal) cancer.
Picture of colon (colorectal) cancer.
The colon and the rectum are the final portions of the tube that extends from the mouth to the anus. Food enters the mouth where it is chewed and then swallowed. It then travels through the esophagus and into the stomach. In the stomach, the food is ground into smaller particles and then enters the small intestine in a carefully controlled manner. In the small intestine, final digestion of food and absorption of the nutrients contained in the food occurs. The food that is not digested and absorbed enters the large intestine or colon and finally the rectum. The large intestine is about six feet long and acts primarily as a storage facility for waste; however, additional water, salts, and some vitamins are further removed. In addition, some of the undigested food, for example, fiber, is digested by colonic bacteria and some of the products of digestion are absorbed from the colon and into the body. (It is estimated that 10% of the energy derived from food comes from these products of bacterial digestion in the colon.) The remaining undigested food, dying cells from the lining of the intestines, and large numbers of bacteria are stored in the colon and then periodically passed into the rectum. Their arrival into the rectum initiates a bowel movement that empties the colonic contents from the body as stool.

Most of the large intestine rests inside a cavity in the abdomen called the peritoneal cavity. Parts of the colon are able to move quite freely within the peritoneal cavity as the undigested food is passing through it. As the colon heads towards the rectum, it becomes fixed to the tissues behind the peritoneal cavity, an area called the retroperitoneum. The end portion of the large intestine, the part that resides in the retroperitoneum, is the rectum. Unlike much of the rest of the colon, the rectum is fixed in place by the tissues that surround it. Because of its location, treatment for rectal cancer often is different than treatment for cancer of the rest of the colon, as we’ll explain later.

Picture of colon cross section.
Picture of colon cross section.
Although the large intestine is a tube, it is structurally a complicated tube, more like a steel belted radial tire than a garden hose. The tube is comprised of four layers. The first is an inner layer of cells that line the cavity through which the undigested food travels, called the mucosa. The mucosa is attached to a thin second layer, the submucosa, that is attached itself to a layer of muscle, the muscularis. The entire tube is surrounded by fibrous (scar-like) tissue called the serosa. The most common cancers of the large intestine (the type called adenocarcinoma) arise from the mucosa, the inner layer of cells. These cells are exposed to toxins from food and bacteria as well as mechanical wear and tear and are constantly dying off and being replaced. Mistakes (usually a series of mistakes involving genes within the replacement cells) lead to abnormal cells and uncontrolled proliferation of the abnormal cells that give rise to cancer.

Picture of colon cancer formation.
Picture of colon cancer formation.
Cancers of the colon and rectum (colorectal cancer) start when the process of the normal replacement of lining cells goes awry. Mistakes in mucosal cell division occur frequently. For reasons that are poorly understood, sometimes mistakes occur that escape our editing systems. When this occurs, these cells begin to divide independently of the normal checks and balances that control growth. As these abnormal cells grow and divide, they can lead to growths within the colon called polyps. Polyps vary in type, but many are precancerous tumors that grow slowly over the course of years and do not spread. As polyps grow, additional genetic mutations further destabilize the cells and can make the cells more bizarre. When these precancerous tumors change direction (growing through the tube rather than into the middle of it) and invade other layers of the large intestine (such as the submucosa or muscular layer), the precancerous polyp has become cancerous. In most cases this process is slow, taking at least 8 to 10 years to develop from those early aberrant cells to a frank cancer.

Once a colorectal cancer forms, it begins to grow in two ways. First, the cancer can grow locally and extend through the wall of the intestine and invade adjacent structures, making the mass (called the primary tumor) more of a problem and harder to remove. Local extension can cause additional symptoms such as pain or fullness, or cause blockages of the colon or nearby structures. Second, as the cancer grows it begins the process of metastasis, shedding thousands of cells a day into the blood and lymphatic system that can cause cancers to form in distant locations. Colorectal cancers most commonly spread first to local lymph nodes before traveling to distant organs. Once local lymph nodes are involved, spread to the liver, the abdominal cavity, and the lung are the next most common destinations of metastatic spread.

A change in your bowel habits, including diarrhea or constipation or a change in the consistency of your stool
Rectal bleeding or blood in your stool
Persistent abdominal discomfort, such as cramps, gas or pain
A feeling that your bowel doesn’t empty completely
Weakness or fatigue
Unexplained weight loss
Many people with colon cancer experience no symptoms in the early stages of the disease. When symptoms appear, they’ll likely vary, depending on the cancer’s size and location in your large intestine.

When to see a doctor

If you notice any symptoms of colon cancer, such as blood in your stool or a persistent change in bowel habits, make an appointment with your doctor.

Talk to your doctor about when you should begin screening for colon cancer. Guidelines generally recommend colon cancer screenings begin at age 50. Your doctor may recommend more frequent or earlier screening if you have other risk factors, such as a family history of the disease.