Bowel cancer — also known as colorectal cancer — is the third most deadly cancer in the world. Luckily, it’s also highly treatable if detected early. So in this article, we’ll discuss some bowel cancer signs that you should watch out for.

But first, let’s briefly discuss what colorectal cancer is and why it develops.

What is colorectal cancer?

Colorectal cancer is a type of cancer that develops in the colon or rectum — the large intestine. The colon and rectum are parts of the digestive system, which processes food we eat and eliminates waste from our bodies.

Cancer happens when normal cells in the body begin to grow abnormally. These abnormal cells can form into a tumor. If the tumor is left untreated, it can grow and spread to other parts of the body. This is why early detection is so important — it allows doctors to treat the cancer before it spreads.

There are a few different types of colorectal cancer, but the most common type is adenocarcinoma. This type of cancer begins in the cells that line the colon or rectum, and is composed of gland-like structures.

Other types of colorectal cancer include:

  • Sarcoma: This type of cancer develops in the connective tissues of the colon or rectum, such as the muscles.
  • Lymphoma: This type of cancer develops in the lymphatic system, which is a part of the immune system.
  • Carcinoid tumors: These are slow-growing tumors that develop in the hormone-producing cells of the intestine.

Now that we’ve discussed what colorectal cancer is, let’s talk about 5 cancer signs to watch out for.

What are the signs of colorectal cancer?

Signs of colorectal cancer include bleeding from the anus, changes in stool appearance and frequency, weight loss, and signs of metastatic disease. Let’s discuss these in detail now.


One of the most common signs of colorectal cancer is bleeding from the rectum or anus. This bleeding can be bright red, or it may be darker in color. It may also appear as blood in your stool.

If the bleeding due to cancer is significant, you might develop a lack of hemoglobin, which is called anemia. Symptoms of anemia include fatigue, palpitations, a desire to eat dirt, and changes in nail shape.

This bleeding may also be associated with a change in bowel sounds. Bowel sounds are normal sounds produced by the gut as it contracts. They can be heard using a stethoscope placed over the abdomen. The Center of Gastrointestinal Health describes bowel cancer stomach noises as “hyperactive”, which means they become louder and more frequent in patients with cancer.

If you notice any bleeding, it’s important to see a doctor right away. However, it’s important to remember that bleeding can also be a sign of other conditions, such as hemorrhoids. 

Changes in stool

Another sign of colorectal cancer is changes in your stool. This can include changes in the size, shape, or color of your stool. You may also notice that your stool is narrower than usual, which is especially true for left-sided cancers.

But keep in mind that changes in stool can also be a sign of other conditions, such as irritable bowel syndrome

Changes in bathroom habits

Another sign of colorectal cancer is changes in your bathroom habits. This can include a change in how often you have a bowel movement, as well as a change in the consistency of your stool

But once again, this is a non-specific sign that can be seen in other conditions like irritable bowel syndrome and inflammatory bowel disease.

Weight loss

Unexplained weight loss is another sign of colorectal cancer. This is because cancer can cause you to absorb fewer nutrients from food. It might also suppress your appetite, leading to a reduced intake of calories.

If you notice that you’re losing weight without trying, it’s important to see a doctor. While unintentional weight loss is a dangerous sign, it can also be due to non-cancerous conditions like long-term infections.

Signs of metastatic disease

Metastatic disease is when the cancer has spread to other parts of the body. The most common site of metastatic bowel cancer is the liver.

Signs of metastatic disease include:

  • Jaundice: This is when the skin and whites of the eyes turn yellow. This is caused by a build-up of bilirubin in the blood.
  • Unexplained pain: This can be caused by the cancer pressing on nerves or organs.
  • Enlarged lymph nodes: This can be caused by the cancer spreading to the lymphatic system.
  • Difficulty breathing: This occurs when the cancer has spread to the lungs.

But all of these signs can be caused by other, benign conditions too. For example, hepatitis A is a liver infection that can lead to jaundice. Similarly, almost all infections in the body lead to enlarged lymph nodes. 

Do these signs always mean cancer?

As we’ve discussed, many of these signs can also be caused by conditions other than cancer. This means they don’t always point towards colorectal cancer, especially if they go away on their own.

However, some people are at an increased risk for colorectal cancer, and they should take these signs seriously. Risk factors for colorectal cancer include:

  • Family history of bowel cancer
  • Smoking
  • Alcohol consumption
  • Obesity
  • A diet rich in processed meat and low in fiber
  • History of radiation to the abdomen 

If any of these applies to you and you’re experiencing the signs we’ve discussed above, you should seek immediate medical attention for cancer screening

If you get a diagnosis of colorectal cancer, you should know that it’s highly treatable and 90% of patients survive the first 5 years of their diagnosis if the disease is localized. Nonetheless, life with cancer is difficult and you might find these coping strategies for cancer patients helpful during your battle against the disease.