Medically Reviewed

Colorectal Cancer: Everything You Need to Know

We’ve got the doctor-approved scoop on causes, symptoms, treatments, and a jillion other facts and tips that can make life with colorectal cancer easier.

Updated Nov 12, 2021

By

Lisa Davis

Medical ReviewerRajal Patel, M.D., radiation oncologist

Our Experts: Leonid Cherkassky, M.D.; Gautam Mankaney, M.D.; Eduardo Vilar-Sanchez, M.D., Ph.D.

Leonid Cherkassky, M.D.Assistant Professor of Oncology Roswell Park Comprehensive Cancer Center Buffalo, NY

Gautam Mankaney, M.D.Gastroenterologist Cleveland Clinic Cleveland, OH

Eduardo Vilar-Sanchez, M.D., Ph.D.Associate Professor of Clinical Cancer Prevention The University of Texas MD Anderson Cancer Center Houston, TX

Whether you’ve just been diagnosed or worry you could have colorectal cancer, you’re probably nervous, confused, and maybe even a little scared. That’s normal, and everyone featured on HealthCentral with a chronic illness felt like you do now. But we—and they—are here for you. On this page alone, you’ll discover the realities and challenges of the condition, but also the best treatments, helpful lifestyle changes, where to find your colorectal cancer community, and all the crucial information to help you not just manage—but thrive. We’re sure you’ve got a lot of questions...and we’re here to answer them.

If cancer is a four-letter word, colorectal cancer (a cancer of two stigmatized organs, the colon and the rectum) can seem unspeakable. But we need to talk about it. Frankly and unapologetically. Because colorectal cancer—often used interchangeably with colon cancer—is a disease of startling paradoxes. It’s highly preventable: doctors have better tools to ward off colorectal cancer than they do for breast or prostate cancer, or most other cancers for that matter. Yet it kills more people than breast or prostate cancer. In fact, it’s the second most common cause of cancer deaths among men and women combined in the United States, after lung cancer.

That good news/bad news narrative plays out in the latest stats on the disease’s targets. When you look at all ages combined, colorectal cancer is less common—and less deadly—than it used to be, and the drop is especially dramatic among the group at highest risk, adults 50 and older (Two steps forward, right?). But colorectal cancer rates are climbing in younger ages that were never on the radar for specialists: a 30-year-old today faces a higher risk of both colon and rectal cancer than a Baby Boomer did at the same age (annnnnd, a huge step back). That younger shift is due, in part, experts say, to rising obesity rates in Gen Xers and millennials.

For this question, we need to go deep into the colon, not the sexiest place on the planet.

So, let’s use a metaphor: If your body is a computer, think of your colon and rectum as the hard drive. Though part of the digestive system, they don’t digest. Instead, in the approximately six feet of tubing that makes up these organs, aka the large intestine, it’s all about storing, processing, and ridding waste. Post-digested remains are held and concentrated here, including carcinogens from food or chemicals in the charred parts of cooked meat. And that mash-up sits for a good while (aka: however long it takes you to poop) right next to the intestinal lining.

Exposure to carcinogens is one factor behind the large intestine’s predisposition toward cancer (after all, carcinogen means a substance that causes cancer). Another is that the cells in the lining turn over fast—dividing quickly enough to make a whole new lining every week. With such rapid cell turnover, there are more chances for errors to occur in DNA replication, increasing mutation odds.

These mutations can trigger cells to go rogue and multiply, which can result in growths called polyps. Around 30% of adults who are middle-aged or older have colonic polyps. If left alone, a small number of these growths (we’re talking less than 1%, okay?) eventually become cancerous. But when one does, it can grow into a mass that can obstruct the colon or rectum and spread to other organs, like the liver and lungs.

This march is a slow one, though: It takes about ten years for a polyp to become cancerous. That’s why public health organizations like the Centers for Disease Control and Prevention (CDC) and the American Cancer Society recommend that older people (usually defined as 50-plus) get screened for polyps regularly. If you get the most accurate screening test, a colonoscopy, every ten years—or if you get a less accurate screening test on a more frequent schedule—you can short-circuit the process of cancer formation and prevent this deadly disease from ever developing.

The biggest risk factor of colorectal cancer is simply growing older—90% of colorectal cancer cases are diagnosed after age 50. Other big ones include:

• Family history. We’re talking immediates here. If your mom, dad, or brother/sister was diagnosed with colorectal cancer, it doubles your own risk, per the National Cancer Institute.

• Ethnicity. In the United States, African Americans are more likely to develop colorectal cancer than members of any other ethnic group, according to the American Society for Gastroenterological Endoscopy. Jews of Eastern European descent (Ashkenazi Jews) are also at increased risk.

• Inflammatory bowel disease. The chronic bowel inflammation that’s a hallmark of ulcerative colitis and Crohn’s disease boosts the risk of colorectal cancer. (Pause for a bit of better news: The much more common irritable bowel syndrome doesn’t affect your risk.)

• Genetic predisposition. Some inherited disorders greatly increase the odds of developing colorectal cancer, though these account for less than 5% of cases overall. In Lynch syndrome, also called hereditary nonpolyposis colorectal cancer (HNPCC), people are more likely to develop colorectal cancer, plus cancer of the stomach, liver, brain, and a number of other organs. In another genetic condition called familial adenomatous polyposis, hundreds or even thousands of colon polyps can eventually develop; for someone with this disorder, having the colon and possibly the rectum surgically removed before cancer develops may be an unavoidable move.

Should I Be Screened for Colorectal Cancer?

There are two times you should be tested for colorectal cancer: when you’re due for a routine screening test and if you’re experiencing symptoms that could indicate a problem.

The standard recommendation for people without obvious risk factors like a strong family history is to start getting screened at age 50 (adults at increased risk should have their first test at age 45 or even earlier). However, because of the rise in colorectal cancer among younger people, the American Cancer Society now says that adults at average risk should consider starting colorectal cancer screening at age 45.

There are a lot of screening types (some are even advertised on TV). But most experts recommend a colonoscopy. That’s because a colonoscopy—unlike other screenings—can detect not only cancer, but precancer (aka: polyps). And if a polyp or other suspicious mass is found during the exam, the tissue can be removed for testing then and there—if any of the other tests raises a red flag, you’ll need a colonoscopy to find out what’s going on.

Those with an average risk of colorectal cancer will need to get a colonoscopy once every ten years (though if a polyp is found during the exam, you’ll likely be asked to come back sooner—in three to five years, or possibly even earlier, depending on the number and type of polyps that were found, among other things). Other tests will need to be repeated more often, particularly if they don’t require pre-test prep (to clean out the colon) or can be done at home, like Colonguard. That do-it-yourself kit allows you to collect a stool sample (can be a bit ick for the weak of stomach) and send it off to a lab, where it will be tested for signs of cancerous cells and polyps.

Here’s what to expect from the most popular in-office tests, courtesy of the National Cancer Institute. (Prepare yourself):

• Colonoscopy. A thin, flexible tube-like instrument (a colonoscope) is inserted through the rectum into the colon to look for polyps—a video camera on the end of the colonoscope gives the doctor a view of the entirety of the large intestine. If any polyps are found, they can be removed right then. Frequency: every 10 years (more often if you’re at higher-than-average risk or if a polyp is discovered).

• Sigmoidoscopy. Like a mini colonoscopy, this procedure only inspects the rectum and lower colon. Abnormal tissue can be removed for testing. Frequency: every 3 to 5 years (or every 10 years so long as you also get a yearly Fecal Immunochemical Test, called FIT—see below for info on that method).

• Virtual colonoscopy. As the name suggests, this is a digital version of the common test. A series of X-rays is taken of the large intestine and assembled by a computer to create a detailed picture. Frequency: every 5 years.

• Fecal occult blood test. A sample of stool is checked for blood that may mean cancer is present. (FIT is a sophisticated version of this test—it uses an antibody to check for blood.) Frequency: every year.

• DNA stool test. A sample is checked for DNA markers found in colorectal cancer and in polyps that are well on the way to turning cancerous. The test also checks for blood. Frequency: not yet established (the test is too new).

Symptoms of colorectal cancer are frustratingly nonspecific. They include changes that you might experience for other reasons, even if you don’t have cancer—or any other disease. To make things more complicated, colorectal cancer can also develop without any noticeable symptoms at all. Collective ugh.

That said, you should be aware of symptoms of colorectal cancer, which can include both whole-body changes and ones that are more obviously bowel related. They include:

• Fatigue

• Unexplained weight loss

• Stomach pain or cramps, or a sensation of fullness

• Blood in or on your stool

• Unexplained anemia (this could show up on a blood test you get for some other reason)

• Diarrhea, constipation, or feeling like you still need to have a bowel movement after having one

• A change in the consistency of stool, or stool that is narrower or thinner than usual

If any of these changes persist, it’s worth having a conversation with your doctor.

How Can I Lower My Risk of Colorectal Cancer?

Even though the biggest risk factors for this disease are out of your control (like getting older, for instance, or having a family history), there are things you can do to lower your chances of developing it. Those include:

• Maintaining a healthier weight. Obesity raises the risk of developing and dying from colorectal cancer. Experts say the excess pounds cause chronic inflammation that encourages cells to turn malignant.

• Watching your alcohol intake. People who drink heavily (eight or more drinks per week for women and 15 or more per week for men, according to the CDC) are about 45% more likely to develop colorectal cancer than nondrinkers, per the American Society of Clinical Oncology.

• Abstaining from smoking. The carcinogens in cigarettes sneak into your bloodstream and can prompt cancerous changes throughout your body.

• Following a balanced diet. Many studies have pointed to a link between colorectal cancer and heavy red meat consumption. Eating lots of processed stuff (think: hot dogs and luncheon meats) seems particularly problematic.

• Working out. Getting up off the couch makes a difference to your risk of colorectal cancer—in fact, researchers weighed the results of 52 different studies and concluded it could reduce the odds of developing the disease by 24%.

• Taking Hormone Therapy. If you are a postmenopausal woman who is using combination hormone therapy, you're risk of developing invasive colorectal cancer is lowered.

There are a lot of diagnostic tests, but a colonoscopy is the gold standard. If a polyp or mass is discovered, the doctor can pass instruments through the colonoscope to remove either a sample of tissue or the whole thing so it can be examined by a pathologist, a medical specialist expert in identifying cancerous changes.

OK....so what if the pathologist IDs cancer in the polyp or the tissue sample? Your doctor will “stage the cancer”—essentially, doing other tests to determine how advanced the cancer is and the kind of treatment that will be most successful. Exactly which tests depend on many factors—not all of them will be used for every person. Still, the tests will probably include some of the following:

Lymph node biopsy. The doctor removes some or all of a lymph node (or several of them) for examination by a pathologist to check for cancer cells.

Imaging tests to show if and where the cancer has spread. These include:

• Chest X-ray

• Computed tomography (CT or CAT) scan

• Positron emission tomography (PET) scan

• Magnetic resonance imaging (MRI)

• Ultrasound

Laboratory tests of the tumor. These look for genetic mutations in the cells of the tumor and help doctors understand the best treatment if imaging and other exams show that the cancer is advanced. For instance, if cells of the tumor show a mutation in a gene called K-RAS, doctors know that a treatment using a substance called an epidermal growth factor receptor (EGFR) inhibitor won’t be effective, so they’ll turn to a different therapy instead.

One important test looks for problems with cell proteins called mismatch repair proteins, which are tasked with fixing mistakes that occur during DNA replication. The results can affect the treatment that’s chosen for advanced cancer. In addition, if your tumor tissue lacks these proteins, it could mean you have Lynch syndrome—so you may need genetic testing, as well.

Blood tests, including for carcinoembryonic antigen (CEA). In some people, levels of a substance known as CEA rise when their colorectal cancer develops and falls once their cancer is treated. For these people, regular CEA tests can be a helpful way of watching for a recurrence of the cancer.

What Is the Best Treatment for Colorectal Cancer?

How’s this for proactive—in some cases, you can be treated for colorectal cancer before you even know you have it. Say you have a polyp removed during a screening colonoscopy, and it contains cancerous cells. As long as the entire polyp was taken out—and there wasn’t any cancer at the edges of the polyp—you may not need any other treatment. That’s it, done. Roll the credits. The end. Fin.

Even if the cancer extends beyond the original polyp, removing the part of the colon that contains it (possibly along with some lymph nodes) may be all the treatment you need. In other cases, you may need chemotherapy after surgery. If your cancer is more advanced, you may get chemotherapy before surgery too—that can shrink a large tumor, making it easier and safer to remove.

If your cancer has metastasized—that is, if it has spread to distant organs, like the lung or liver—you’ll probably need other treatments, too. These can include:

• Surgery to remove the metastatic tumors (this can be highly effective, especially if the tumors in other organs can be completely removed).

• Chemotherapy.

• Radiation therapy.

• Ablation. Metastatic cancer can sometimes be removed by using nonsurgical methods to destroy them—or ablate them, in medical jargon. For instance, tumor cells can be frozen or heated with radiofrequency waves.

• Targeted therapy. This relatively new treatment uses substances that home in on and kill cancer cells without harming normal cells.

• Immunotherapy. Another relatively new form of treatment, this uses the body’s own immune system to fight the cancer.

Prospects for people with advanced disease have improved tremendously in the past couple of decades, partly because new surgical techniques have made it possible for specialists to remove more metastatic tumors than ever before. A 2018 study at Memorial Sloan Kettering Cancer Center, in New York, found that with this approach, in combination with chemotherapy, a large number of patients survive more than ten years. That’s why it’s important to involve a multidisciplinary team—including surgeons and medical oncologists—as soon as the diagnosis is made, especially if the cancer is advanced.

Does Colorectal Cancer Have Serious Complications?

The pendulum swings wildly on this one. Depending on the stage at which colorectal cancer is detected, it may be easily treated and completely cured—or can be incurable. The disease is expected to kill approximately 56,000 people in the U.S. this year. Complications of colorectal cancer can include:

• Blockage of the colon and bowel obstruction

• Return of the cancer or the development of a new colorectal cancer

• Metastasis, or the spread of the cancer to other organs

There’s a big fork in the road here. If it’s caught early, there may not be much of an impact on their daily life. If it’s advanced at diagnosis? Major. In the very early stages, colorectal cancer may be fully treated by removing the suspicious mass during colonoscopy. In later stages, a person may need chemotherapy, radiation therapy (for rectal cancer), and more extensive surgery, both on the large intestine and, if the cancer has spread, on other organs as well.

Depending on the size and location of the cancer, the surgeon may need to remove a substantial portion (we’re talking feet, not inches) of your colon. If the doctor is not able to sew the healthy parts of the colon together, you may need a temporary or permanent colostomy. The surgeon creates an opening in the abdominal wall so that stool can exit there, to be collected in an ostomy bag outside the body.

This is life changing, and if that becomes your reality, your first thought may be that it’s the worst kind of life changing. And yet—and yet—there’s an entire contingent of people who are proving that theory wrong. People who have broken the fourth wall on Instagram. These folks talk to other ostomy-slingers, usually under #ostomyinspo, in the most real, inspiring, moving, motivating way. Nothing is off limits—including having sex with an ostomy bag. Need support offline? An ostomy nurse can help you learn how to manage the device, and a support group can provide valuable practical and emotional feedback.

If your cancer was completely treated and your doctors believe they got it all, you may worry about it returning. (Seriously, you wouldn’t be human if you didn’t.) Your doctor will likely recommend that you get regular tests to check for a recurrence of the cancer—perhaps as often as every few months at first, and then eventually on a less-frequent schedule. If your cancer was too advanced to completely treat, you may need to continue with periodic chemotherapy, radiation, or other treatments.

Colon cancer may be the second leading cause of cancer deaths among men and women combined in the U.S., but there are plenty of colon cancer thrivers who are here, sharing their story, giving you tips on managing and navigating life with this disease. They’re here for you—they are you—so you might as well become internet-pals.

Top Colon Cancer Bloggers & Instagrammers

• Audrey Jo, @auggiejo, auggiesbloggie.com

Follow because: Her motto? Plain and simple: BE B.R.A.V.E. She watched her mom lose her battle with ovarian cancer in 2006, so she knew fighting stage 4 metastatic colon cancer wouldn’t be easy. But she fought—and won. Walk with her through the journey of finding herself again, now that she is cancer-free (yas!). Oh, and her headwrap game? On point.

• Danielle Ripley-Burgess, @danielleisb, danielleripleyburgess.com

Follow because: She’s a two-time colon cancer survivor—first diagnosed at just age 17. She is proof that you can overcome, not just during cancer, but in the aftermath. When her cancer took her fertility, she leaned into adoption once she met her husband and settled down. Now she travels and speaks about life as a cancer survivor, who’s still fighting to have a “normal” life.

• Meagan Herrera-Schaaf, @meaganhshair

Follow because: Wonder if you can battle cancer, be a wife and mom, go to chemo, and then run off to your dream job? Well, if Meagan is any proof—you can. On the front lines she styles hair for shows like NBC’s The Voice and World of Dance and attends posh Emmy parties. Then she goes back to her hotel room and peels off her fake nails because she couldn’t get a mani due to chemo restrictions. Her feed gives you the glam and grim life of colon cancer, and it’s all sorts of addicting.

• Hugo Toovey, @hugotoovey

Follow because: He’s an Army Captain who doesn’t just fight as one of the good guys — he fights bowel and testicular cancer, too. Now completely colon-free, Hugo has a stoma named Ted, who he says is temperamental but saved his life. When he’s not traveling to share his story, or posting adorable dog pics, he’s hosting his podcast 25 STAY ALIVE (deets below) with fellow bowel cancer thriver (and ileostomy owner) @dahlia.com.au.

Top Colon-Cancer Related Podcasts

• 25 STAY ALIVE. In case you didn’t know: 25 is the new 50. As in, while most people may get diagnosed with colon cancer after age 50, you can be proactive at age 25. Hosted by Army Captain and two-time cancer survivor Hugo Toovey and bowel cancer thriver Dahlia Maykovic, this podcast covers every stage of cancer, from diagnosis, to survivorship, to death, and all the maintenance of life with cancer in between.

• Chris Beat Cancer. How, you ask? Nutrition, natural therapies, and a whole lot of determination. Host Chris Wark was diagnosed with stage three colon cancer at 26 years old. After surgery, he refused chemotherapy. Instead he invested in his nutrition and himself. This isn’t for everyone — even his doctor told him he was “insane” — but it was for him, and hey, maybe it’s for you, too. Listen to find out for yourself. But, consult your doctor, too, kids.

• Jesse vs Cancer. Hosted by notable standup comedian Jesse Case, this podcast is NSFW. But that’s kind of what you need during cancer sometimes—someone to tell it like it is with sadistic humor, right? Hear about his battle through cancer while living at his parent’s house through treatment (fun times).

Top Support Groups and Nonprofits

• Colorectal Cancer Alliance. Not only does this nonprofit provide free resources for colon cancer thrivers and survivors, but they also provide experts—as in, people who have been there, just like you, and they can mentor you and guide you towards the resources you need for that phase of your disease.

• Colon Cancer Coalition. They have events across the U.S. that, sure, raise money to go towards colon cancer research and screenings—but almost as important? This nonprofit’s events connect patients, caregivers, and loved ones affected by colon cancer and give them a place to vent, support each other, and run it out.

• Fight Colorectal Cancer. It’s a little ridiculous that the number two cause of cancer deaths in the U.S. comes from a preventable disease, right? This nonprofit certainly thinks so. Their fight goes towards advocacy and research and if those terms sound a little over your head, that’s okay, because Fight CRC trains you on how to get involved in the science world and on Capitol Hill. Join their fight, sport a cool t-shirt, and work with them towards a cure.