What are the symptoms of colon cancer?
Some of the most common symptoms of colon cancer are changes in bowel habits and blood in the stool. However, the early stages of colorectal cancer and pre-cancerous changes like colon polyps often don’t cause any symptoms.
Because you may not have symptoms and many digestive conditions cause symptoms similar to colon cancer, screening and early detection are essential to caring for your health. With colon cancer screenings, it’s possible not only to detect and treat colon cancer but also to prevent it.
Early symptoms of colon cancer
When colon cancer is in its earliest stages, you may not have any apparent symptoms. However, it’s important to be aware of the early signs of colon cancer. That way, you can be proactive in caring for your digestive health.
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Blood in stool
Blood in stool
Blood in the stool can range from dark to bright red, and sometimes you’ll have blood in the stool that you can’t see. While one of the most common causes of red blood in the stool is hemorrhoids, ongoing rectal bleeding is also a sign of cancer.
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Changes in bowel habits
Changes in bowel habits
One of the earliest symptoms is changes in bowel habits. Because short-term changes in bowel habits are common, many people miss or ignore the early signs of colon cancer. Early-stage colon cancer shares similar digestive symptoms with several other conditions—from irritable bowel syndrome (IBS) to digestive infections. This can make it difficult to distinguish between the signs of colon cancer and less serious digestive changes. If you’re having some of these early symptoms, it doesn’t mean you have colon cancer. It’s likely that some other digestive issue is causing your symptoms. However, it’s always a good idea to bring up ongoing symptoms to your doctor and get checked.
An infection or diet changes may affect your bowel habits for a short time. But pay attention to any symptoms that last longer than a few days, including constipation, diarrhea, changes in how often you have bowel movements or feeling like the bowel doesn’t empty.
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Changes in stool shape
Changes in stool shape
If you notice changes in your stool’s size, shape or consistency, it could be a sign of cancer. With colon cancer, it’s more common to have very narrow, stringy or thin stool.
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Persistent abdominal pain
Persistent abdominal pain
If colon cancer causes pressure or inflammation in your colon, it can start to cause persistent abdominal pain. This includes achy pain, dull discomfort or feeling bloated.
Blood in stool
Blood in the stool can range from dark to bright red, and sometimes you’ll have blood in the stool that you can’t see. While one of the most common causes of red blood in the stool is hemorrhoids, ongoing rectal bleeding is also a sign of cancer.
Changes in bowel habits
One of the earliest symptoms is changes in bowel habits. Because short-term changes in bowel habits are common, many people miss or ignore the early signs of colon cancer. Early-stage colon cancer shares similar digestive symptoms with several other conditions—from irritable bowel syndrome (IBS) to digestive infections. This can make it difficult to distinguish between the signs of colon cancer and less serious digestive changes. If you’re having some of these early symptoms, it doesn’t mean you have colon cancer. It’s likely that some other digestive issue is causing your symptoms. However, it’s always a good idea to bring up ongoing symptoms to your doctor and get checked.
An infection or diet changes may affect your bowel habits for a short time. But pay attention to any symptoms that last longer than a few days, including constipation, diarrhea, changes in how often you have bowel movements or feeling like the bowel doesn’t empty.
Changes in stool shape
If you notice changes in your stool’s size, shape or consistency, it could be a sign of cancer. With colon cancer, it’s more common to have very narrow, stringy or thin stool.
Persistent abdominal pain
If colon cancer causes pressure or inflammation in your colon, it can start to cause persistent abdominal pain. This includes achy pain, dull discomfort or feeling bloated.
Systemic symptoms of colon cancer
Along with digestive symptoms, colon cancer may cause systemic symptoms. Systemic symptoms happen when cancer spreads outside the digestive system and begins to affect other areas of the body and its ability to function as it should. These initial systemic symptoms are similar across many types of cancer.
As colon cancer grows and spreads, it changes how you absorb nutrients, increases inflammation, leads to other conditions like anemia, or affects normal hormone levels. As a result, some of the most common systemic symptoms of colon cancer are weight loss, changes in appetite and general fatigue or weakness.
Unintentional weight loss
Many changes caused by colon cancer lead to unintentional weight loss. For example, ongoing symptoms like diarrhea often make you feel like not eating as much. Changes such as increased inflammation or effects on your digestive enzymes can impact the way your body uses nutrients.
Fatigue and weakness
While occasional fatigue happens for many reasons, colon cancer may cause ongoing exhaustion, fatigue and weakness. This type of fatigue doesn’t get better with rest or additional sleep.
Loss of appetite
The digestive symptoms of colon cancer, such as changes in bowel habits, often lead to a loss of appetite. As colon cancer grows, it can also make you feel full even when you haven’t eaten much food.
Advanced-stage colon cancer
Symptoms of advanced-stage colon cancer happen when the cancer continues to spread in the body. These symptoms are more common when the cancer has reached colon cancer stages 3 and 4. If you’ve had other early-stage or systemic signs of colon cancer, you may continue to have those along with additional advanced-stage symptoms.
During the advanced stages of colon cancer, cancer cells develop in multiple areas throughout the body. This includes vital organs like your lungs and liver or the bones. The types of advanced symptoms you have will depend on the parts of the body that are affected by the spreading cancer cells.
Types of advanced symptoms:
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Swollen abdomen
Your abdomen can swell due to the growing size of a tumor in your colon. Swelling in the abdomen can also be a sign that colon cancer has spread to the liver, causing fluid to build up. This fluid accumulation is associated with liver cancer.
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Bone pain
The most common symptom when cancer spreads to the bones is strong pain in your bones or joints. Cancer in the bones also puts you at a higher risk of breaking a bone.
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Difficulty breathing
If the cancer spreads to the lungs, you may have respiratory changes and feel it’s hard to breathe. Lung cancer symptoms include getting short of breath, chest pressure and coughing.
Colon cancer symptoms vs. IBS
Irritable bowel syndrome, known as IBS, is one of the most common sources of digestive discomfort. It causes a range of symptoms from mild discomfort to severe issues that get in the way of everyday life. Sometimes, people with IBS experience periods of more intense symptoms, called flare-ups, that come and go.
You may not know the difference between symptoms caused by IBS and symptoms caused by something more severe like colon cancer, especially in its early stages. That’s why it is important to talk with your doctor if you have ongoing digestive symptoms.
While colon cancer and IBS have similar symptoms, there are also some differences. Your doctor can help you understand those differences.
Symptoms of colon cancer
- Constipation or diarrhea
- Abdominal pain
- Feeling like the bowel doesn’t empty
- Blood in the stool
- Sudden weight loss
- Intense fatigue
Symptoms of IBS
- Constipation or diarrhea
- Abdominal pain
- Bloating and gas
- Mucus in the stool
When should I see a doctor for symptoms of colon cancer?
It’s better to see a doctor for colon and rectal cancer symptoms sooner rather than later. While another digestive condition may be causing your symptoms, you should get checked for any colon cancer symptoms.
Listening to your body and talking to your doctor about new symptoms increases your ability to catch colon cancer early. Even if you don’t have any symptoms, you should still ask your doctor about colon cancer screenings, like a colonoscopy.
A colonoscopy is one of the best ways to detect colon cancer sooner. It also allows your doctor to remove colon polyps before they can turn into cancer.
Our locations near you
We help you get care at a location that fits your needs. We offer several locations for your care, including digestive care and colon cancer screenings in North and Central Texas.
Frequently asked questions
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How long can colon cancer go undetected?
Colon cancer can go undetected for several years. Most types of colon cancer grow slowly. That means it may develop over many years and not cause any symptoms.
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When do colon cancer symptoms appear?
Sometimes, colon cancer symptoms don’t appear until the cancer has grown or spread. Many people miss early warning signs or don’t have symptoms of colon cancer until the cancer has reached stage 2 or beyond.
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Do colon cancer symptoms come on suddenly?
Not usually. Because colon cancer tends to grow slowly, you may not have any symptoms during the early stages, or they may develop over time. The most common sudden early signs of colon cancer are weight loss or very narrow, ribbon-shaped stools.
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Can colon cancer symptoms come and go?
Most colon cancer symptoms, such as changes in bowel habits, don’t come and go. The exception to this is abdominal pain. Often, temporary changes in bowel habits or symptoms that have periods of flare-ups are caused by other conditions.
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Are colon cancer symptoms constant?
Yes. Most of the time, colon cancer symptoms are persistent, meaning they continue to happen , and you don’t have periods where you feel better. Some main signs of colon cancer are ongoing changes in bowel habits or abdominal discomfort.