Colon cancer is the fourth most common cancer in men and women, according to the American Cancer Society. The risk of developing it increases with age — it's diagnosed most in adults over 50 — but the incidence of colorectal cancer in younger adults is rising.

"Being young doesn't mean you can't have colorectal cancer," warns Dr. Tareq Kamal, a colorectal cancer surgeon at Houston Methodist. "Even though it mostly occurs in older populations, this cancer can happen in adults below the age of 50."

This message is particularly relevant given the alarming news that colorectal cancer is now the leading cause of cancer death in men under the age of 50. It's why everyone should be aware of colon cancer symptoms and seek medical attention if you notice them.

"Prognosis significantly improves if the cancer is detected early," stresses Dr. Kamal. "Ignoring symptoms may allow colon cancer to progress, making it more challenging to treat."

Here's everything you need to know about this type of cancer, including its risk factors and the symptoms that warrant a conversation with your doctor.

What is the colon?

The colon, also known as the large intestine or large bowel, is a long tube that is an essential part of the digestive system. Its main function is to absorb water and move digested food out of the body, in the form of stool.

When cells with abnormal DNA arise and grow out of control within the lining of the colon or rectum, it's called colorectal cancer. Depending on where the tumor forms, colorectal cancer is sub-classified as either colon cancer or rectal cancer. The latter occurs much less frequently.

"Colon and rectal cancer are grouped together as colorectal cancer because the tumors share similar biology and symptoms," explains Dr. Kamal. "They're also similar from a prevention and diagnostic standpoint. But treatment options differ depending on the location of the tumor. Rectal tumors are more complex to treat, so the treatment pathway after diagnosis can look different."

What causes colorectal cancer?

While it's not exactly clear what leads cancerous cells to develop in the colon lining, a lot is known about what happens after.

"Most colorectal cancers start as a polyp, which is an abnormal growth in the lining of the colon or the rectum," says Dr. Kamal. "There are several types of polyps, but the kind we are most worried about are adenomatous polyps. These carry the risk of progressing to form a type of colon cancer known as adenocarcinoma."

What's also known are the factors that make developing colorectal cancer more likely, which Dr. Kamal says includes things you can't change but also ones you can.

Colorectal cancer risk factors include:

• Family history of colorectal cancer, particularly a first-degree relative
• A history of advanced polyps (large in size or number)
• Certain chronic medical conditions, including inflammatory bowel disease (IBD) and cystic fibrosis
• Smoking
• Heavy alcohol consumption
• A diet high in red meat or processed meats
• Obesity
• Living a sedentary lifestyle

"The people with the highest risk are those who have a strong family history of colorectal cancer — a parent or sibling with this type of cancer," adds Dr. Kamal. "That said, anyone can get colorectal cancer, even a person who isn't higher risk."

What are the early signs of colon cancer?

As mentioned, the sooner colorectal cancer is detected, the better. So how can you be sure you're not missing early symptoms? The answer might not be what you expect. The early stages of colorectal cancer are asymptomatic.

"Colon cancer symptoms typically don't start manifesting until the cancer is slightly more advanced," says Dr. Kamal. "Ideally, we detect cancer before this point."

It's why following colorectal cancer screening guidelines is so important. People with a normal risk of colorectal cancer should begin getting a colonoscopy at age 45. If you're at a higher risk, your doctor can help you understand whether you need to be screened earlier or more frequently. (Related: When to Get a Colonoscopy)

"Screening helps us find and remove polyps before they become cancer, as well as detect colon cancer when it's still in its earliest stages and easiest to treat," adds Dr. Kamal.

Colorectal cancer screening is a critical component of prevention and early diagnosis, but following recommended guidelines isn't the only step you should take to be sure colorectal cancer is caught early. It's also important to know the symptoms of colorectal cancer, so you can alert your doctor should you notice them.

The colorectal cancer symptoms to never ignore

As a colon or rectal tumor grows, physical manifestations begin to present. Many of these symptoms can be disruptive to your daily life, but the greater threat is to your overall health. Consulting your doctor is imperative to help to keep the cancer from advancing to later, more serious stages.

Colorectal cancer symptoms include:

• Changes in bowel habits (frequency of bowel movements or consistency of stool)
• Rectal bleeding (blood in the stool)
• Abdominal or pelvic pain
• Unexplained weight loss

Many things can cause bowel habit changes, of course — food poisoning is a common example. But if the problem persists over the course of a month or two, consult your primary care doctor.

"A symptom like blood in your stool is always abnormal and, even if it happens once, should warrant some kind of medical attention," says Dr. Kamal. "The majority of the time, fresh blood in the stool is due to benign anorectal disease, such as hemorrhoids, but you never want to potentially miss a diagnosis like colorectal cancer."

If you're wondering whether the signs of colorectal cancer in women differ from men — pelvic pain, for instance — Dr. Kamal says the answer is: No.

"Abdominal pain is a nonspecific symptom, meaning a variety of medical conditions can cause it," says Dr. Kamal. "But it's not more frequent in women than men. Colorectal cancer symptoms are the same for everyone and don't change based on gender."

While it can be difficult to differentiate menstrual cramps and bloating from general abdominal pain at times, listen to your body. If you have unexplained pain in your pelvis that doesn't go away, consult your doctor.

"If you notice any of the signs of colorectal cancer, bring it to the attention of your doctor," stresses Dr. Kamal. "Do not delay care, even if you're younger and otherwise healthy."

(Related: Why Even Young Adults Should Care About Colorectal Cancer Screening)