Rectal Bleeding: Is It Hemorrhoids or Cancer?

Recognizing symptoms early is critical to detecting cancer as soon as possible, when it is more easily treatable. These general guidelines outline the different symptoms, causes and next steps for each.

Hemorrhoids

Hemorrhoids affect millions of people worldwide. Also known as piles, hemorrhoids occur when blood vessels in the anus and/or lower rectum become swollen and inflamed. They can occur both internally (inside the anus at the beginning of the rectum) and externally (outside the anus where people wipe). 

The most common causes of hemorrhoids include:

• Chronic constipation or diarrhea

• Frequently lifting heavy objects

• Low-fiber diets

• Obesity

• Pregnancy

• Sitting for long periods of time

• Straining during bowel movements

• Weakening tissues that occur with age

Hemorrhoids cause a variety of symptoms that are generally seen and felt only near the affected area. These symptoms may include:

• Anal ache, pain and/or discomfort

• Rectal bleeding

• Lumps near your anus

• Rectal or anal itching

While hemorrhoids can be uncomfortable, they are usually not serious. Hemorrhoids can be treated with lifestyle changes, over-the-counter medications and in some cases, medical procedures.

Colorectal cancer 

Colorectal cancer, or CRC, is a type of cancer that affects the colon or rectum. It almost always starts from a growth or polyp, developing into cancer over time. CRC is a serious condition that can be life-threatening if not detected and treated early. 

Most cases of colorectal cancer occur in people ages 45 and older, but the disease is increasingly affecting younger people under age 50. Since the 1990s, cases of young-onset colorectal cancer have more than doubled. Each year, about 150,000 Americans are diagnosed with this disease, and more than 50,000 die. 

About half of colorectal cancers in the United States are associated with lifestyle risk factors, including lack of exercise, excess weight, smoking, heavy alcohol use and eating a diet high in red or processed meat and low in fruits, vegetables, whole-grain fiber and calcium. 

A family history of colorectal cancer and type 2 diabetes is also a risk factor. Certain inherited genetic syndromes, like Lynch syndrome, and chronic inflammatory bowel diseases, such as ulcerative colitis or Crohn’s disease, put people at very high risk of colorectal cancer.

People with precancerous polyps or early colorectal cancer generally have no symptoms. However, when symptoms occur, they may include: 

• Changing bowel habits

• Persistent abdominal discomfort

• Rectal bleeding

• Unexplained weight loss

• Weakness or fatigue

Unlike most cancers, colorectal cancer is often preventable with timely screening and highly treatable when detected early.

Timely screening allows the removal of polyps before they turn into cancer, and CRC has a 91% survival rate when detected early, so being proactive about screening, even without symptoms, is vital to improving outcomes. 

Determining when to start screening for colorectal cancer and which test to use is a shared decision between doctor and patient.

Screening recommendations are based on your age, family history, risk factors and symptoms, but everyone at average risk should start screening no later than age 45. There are several screening options, including colonoscopy and easy-to-use at-home tests.

Anal cancer

Anal cancer develops in the anus or the anal canal. This is a different type of cancer than colon or rectal cancer. Almost all anal cancers are related to a human papillomavirus (HPV) infection. Anal cancer is also significantly less common than colon or rectal cancer.

Anal cancer symptoms include:

• A change in bowel habits

• A lump near the anus

• Anal or pelvic pain

• Bleeding from the anus or rectum

• Itching or discharge from the anus

• Pain or pressure in the area around the anus

• Unexplained weight loss, which can signify later stages of cancer

How are the symptoms of hemorrhoids and anal and colorectal cancer different?

Even though some of the symptoms of hemorrhoids, anal cancer and colorectal cancer are similar, they are three very different conditions. It’s important to understand that hemorrhoids by themselves are not a sign of colorectal or anal cancer. 

Still, it is important to know the similarities and differences so that you can stay in control of your health. 

Differences in bleeding

Hemorrhoids, colorectal cancer and anal cancer can all cause bleeding from the anus or rectum. Here are the main differences:

• Hemorrhoid bleeding is usually bright red and occurs during or after a bowel movement. 

• Colorectal cancer bleeding can be either dark or bright red and can occur at any time. 

• Anal cancer can cause dark or bright red bleeding and can occur at any time. 

Differences in discomfort

Persistent bowel discomfort may be another symptom that is hard to differentiate.

While it may be a sign of either hemorrhoids, CRC or anal cancer, it could also be caused by a variety of other medical conditions, such as irritable bowel syndrome, diverticulitis or inflammatory bowel disease. The only way to be certain is to speak to a healthcare provider right away.

No matter what, speak to a doctor

There is no such thing as normal rectal bleeding, and it should always be discussed with a healthcare provider. Untreated hemorrhoids can lead to persistent bleeding, pain, infection or other health complications.

Untreated CRC or anal cancer can lead to the spread of cancer and even death. The good news is that hemorrhoids, colorectal cancer and anal cancer are highly treatable. 

CRC has high survivorship rates if detected early, and hemorrhoids can be easily treated with over-the-counter medications or simple procedures. Any of these symptoms should prompt a visit to a doctor. 

Breaking down stigmas 

While talking about your bowels can be uncomfortable, the consequences of leaving symptoms unaddressed can be life-threatening. 

Hemorrhoids are a highly common condition experienced by millions of people each year. Additionally, colorectal cancer is the fourth most diagnosed cancer and the second leading cause of cancer-related deaths in the United States. 

While hemorrhoids are not a sign of CRC or anal cancer, some signs and symptoms of all may overlap, making it important to seek medical care right away.

Patients looking for more confidential support may reach out to the Colorectal Cancer Alliance, the nation’s leading and largest nonprofit dedicated to ending the disease.

About the experts

Michael Sapienza is the Chief Executive Officer of the Colorectal Cancer Alliance (Alliance), the leading colon and rectal cancer advocacy group in the country. He lost his mother to colorectal cancer in May 2009. He turned his profound grief into action, inspiring and challenging the colorectal cancer community, family, friends, and professional associates to follow his lead and dedicate themselves to ending colorectal cancer within our lifetime - the mission of the Alliance.

Dr. Richard Wender is the Chair of the Department of Family Medicine and Community Health in the Perelman School of Medicine at the University of Pennsylvania. He has dedicated his career to leading medical and public health efforts to improve the quality of primary care, implement population health strategies, and address social determinants of health in the continuous pursuit of equity for all people.

What This Means For You

Rectal bleeding, pain or changes in bowel habits should never be ignored. While hemorrhoids are common and usually harmless, some symptoms overlap with colorectal and anal cancer. If you notice persistent bleeding, discomfort or changes in digestion, reach out to a healthcare provider right away.