Colon Cancer vs. Hemorrhoid Symptoms

Reviewed on 8/10/2022

Colon Cancer Symptoms vs. Hemorrhoids Facts

Colon Cancer Diet
Most colorectal cancers arise from adenomatous polyps.
  • Colon cancer is the growth of abnormal cells in the colon (large intestine).
  • Hemorrhoids are swollen and enlarged veins in the lower part of the rectum and the anus. There are three types of hemorrhoids, internal, external, and thrombosed.
  • Signs and symptoms of colon cancer and hemorrhoids that are similar include:
    • Rectal bleeding
    • Blood in the stool
    • The feeling as if you haven’t finished a bowel movement.
  • Colon cancer symptoms may not be noticeable until the disease has progressed. Signs and symptom of colon cancer (when they do occur) that do not occur with hemorrhoids may include:
    • Changes in the frequency of bowel movements
    • Symptoms of bowel obstruction such as abdominal distention or pain
    • Unexplained or persistent nausea or vomiting
    • Unexplained weight loss
    • Changes in stools, for example,
    • Narrow or ribbon-like stools
    • Constipation
    • Rarely, rectal pain
    • Studies suggest that the average duration of symptoms of colon cancer (from onset to diagnosis) is 14 weeks.
  • Signs and symptoms of internal, external, and thrombosed hemorrhoids that do not occur with colon cancer may include:
  • Causes of colon cancer include adenomatous polyps, genetic abnormalities, inflammatory bowel disease (ulcerative colitis or Crohn's colitis [Crohn's disease)], past or present cancers (breast, uterine, or ovarian), a family history of colon cancer, obesity, smoking, and possibly diet.
  • Causes of hemorrhoids include situations that increase pressure within the hemorrhoidal blood vessels such as straining to have a bowel movement (due to constipation or diarrhea), prolonged sitting, inactivity, low fiber diet, obesity, pregnancy, colon cancers, liver disease, inflammatory bowel disease (IBD), anal intercourse, and spinal cord injury.

What Is Colon Cancer? What Does It Look Like (Pictures)?

Picture of colon (colorectal) cancer
Picture of colon (colorectal) cancer and polyp

Colon cancer is the transformation of normal cells to abnormal cells in the colon. Most colon cancers are adenocarcinomas-tumors that develop from the glands lining the colon's inner wall.

Left untreated, these cancers grow and eventually spread through the colon wall to involve the adjacent lymph nodes and organs. Ultimately, they spread (metastasized) to distant organs such as the liver, lungs, brain, and bones.

Sometimes colon cancer, or malignant tumors, are referred to as colorectal cancer, reflecting the fact that the rectum, the end portion of the colon, also can be affected. Some researchers and doctors recognize colon and rectal cancer to be two different types of cancer in the digestive tract, due to the anatomical differences in the rectum as compared to the rest of the colon.

  • One in 17 people in the U.S. will develop colorectal cancer.
  • According to reports from the National Cancer Institute, colorectal cancer is the third most common cancer in U.S. men.
  • Colorectal cancer is the second most common cancer in U.S. women of Hispanic, American Indian/Alaska Native, or Asian/Pacific Islander ancestry, and the third most common cancer in white and African American women.
  • Deaths from colorectal cancer rank third after lung and prostate cancer for men and third after lung and breast cancer for women.
  • Death statistics from colon cancer vs. rectal cancer is not clear as an estimated 40% of rectal cancers are misdiagnosed as colon cancer.


Everyone has hemorrhoids. See Answer

What Are Hemorrhoids? What Do Hemorrhoids Look Like?

Picture of Internal, External, and Thrombosed Hemorrhoids
Picture of Internal, External, and Thrombosed Hemorrhoids

Hemorrhoids are enlarged and swollen blood vessels located in the lower part of the rectum and the anus. The blood vessels become swollen due to increased pressure within them. There are different types of hemorrhoids.

  1. Internal hemorrhoids are located on the inside lining of the rectum and cannot be felt unless they prolapse and push through the anus opening causing pain and itching.
  2. External hemorrhoids are located beneath the skin on the outer aspect of the anus. Symptoms may include bleeding with a bowel movement and a mass or fullness that can be felt at the anal opening. External hemorrhoids do not cause many problems unless they rapidly expand and clot. Usually this clot resolves spontaneously leaving residual skin.
  3. A thrombosed external hemorrhoid occurs when blood within the blood vessel clots, and may cause significant pain and swelling.

What Are the Differences Between Colon Cancer and Hemorrhoid Symptoms and Signs?

Colon Cancer Symptoms and Signs

People commonly attribute all rectal bleeding to hemorrhoids, thus preventing early diagnosis owing to lack of concern over "bleeding hemorrhoids." New onset of bright red blood in the stool always deserves an evaluation. Blood in the stool may be less evident, and is sometimes invisible, or causes a black or tarry stool.

  • Rectal bleeding may be hidden and chronic and may only show up as an iron deficiency anemia.
  • It may be associated with fatigue and pale skin due to the anemia.
  • Changes in bowel movement frequency
  • It usually, but not always, can be detected through a fecal occult (hidden) blood test, in which samples of stool are submitted to a lab for detection of blood.
  • If the tumor gets large enough, it may completely or partially block your colon. You may notice the following symptoms of bowel obstruction:
  • Abdominal distension: Your belly sticks out more than it did before without weight gain.
  • Abdominal pain: This is rare in colon cancer. One cause is tearing (perforation) of the bowel. Leaking of bowel contents into the pelvis can cause inflammation (peritonitis) and infection.
  • Unexplained, persistent nausea or vomiting
  • Unexplained weight loss
  • Change in frequency or character of stool (bowel movements)
  • Small-caliber (narrow) or ribbon-like stools
  • Constipation
  • Sensation of incomplete evacuation after a bowel movement
  • Rectal pain: Pain rarely occurs with colon cancer and usually indicates a bulky tumor in the rectum that may invade surrounding tissue after moving through the colon's submucosa.

Research suggests that the diagnosis of colon cancer is about 3 ½ months after signs and symptoms begin.

Symptoms and Signs of Hemorrhoids

The most common signs and symptom is painless bleeding. There may be bright red blood on the outside of the stools, on the toilet paper, or dripping into the toilet. The bleeding usually is self-limiting. Symptoms may depend upon the type of hemorrhoid.

Internal Hemorrhoid Symptoms and Signs

Most often, internal hemorrhoids have no symptoms but are only found if there is bleeding with a bowel movement or if the hemorrhoid prolapses so that it can be felt outside of the anus. This may lead to itching and pain as well as the bleeding. Hemorrhoids also may cause anal itching (pruritus ani), and a constant feeling of needing to have a bowel movement (tenesmus).

Prolapse of an internal hemorrhoid occurs when the internal hemorrhoids swell and extend from their location in the rectum through the anus. A prolapsed internal hemorrhoid:

  • A lump can be felt outside of the anus
  • Can be gently pushed back through the anus, this may resolve the location of the hemorrhoid, but does not fix the hemorrhoid itself.
  • May enlarge and swell even more if it cannot be pushed back
  • May become entrapped, which requires more urgent medical attention

External and Thrombosed Hemorrhoid Symptoms and Signs

Thrombosed external hemorrhoids are a painful condition. These occurs when a blood clot develops in a hemorrhoidal blood vessel causing swelling and inflammation.
When a blood clot occurs in a hemorrhoid, the hemorrhoid will become even more swollen. This swelling leads to increased pain. The pain is usually worse with bowel movements and may increase with sitting.

A thrombosed external hemorrhoid may resolve on its own; however, this condition often needs medical care. Bleeding with a bowel movement is never normal and should prompt a visit to a health care professional. While hemorrhoids are the most common cause of bleeding with a bowel movement, there may be other reasons for bleeding including inflammatory bowel disease, infection, and tumors.

What Causes Colon Cancer and Hemorrhoids? Do Hemorroids Lead to Colon Cancer?

Colon Cancer Causes

Most colorectal cancers arise from adenomatous polyps. Such polyps are comprised of excess numbers of both normal and abnormal appearing cells in the glands covering the inner wall of the colon. Over time, these abnormal growths enlarge and ultimately degenerate to become adenocarcinomas.

People with certain genetic abnormalities develop what are known as familial adenomatous polyposis syndromes. Such people have a greater-than-normal risk of colorectal cancer. In these conditions, numerous adenomatous polyps develop in the colon, ultimately leading to colon cancer.

  • There are specific genetic abnormalities found in the two main forms of familial adenomatous polyposis.
  • The cancer usually occurs before age 40 years.
  • Adenomatous polyposis syndromes tend to run in families. Such cases are referred to as familial adenomatous polyposis (FAP). Celecoxib (Celebrex) has been FDA approved for FAP. After six months, celecoxib reduced the mean number of rectal and colon polyps by 28% compared to placebo (sugar pill) 5%.

Another group of colon cancer syndromes, termed hereditary nonpolyposis colorectal cancer (HNPCC) syndromes, also runs in families. In these syndromes, colon cancer develops without the precursor polyps.

  • HNPCC syndromes are associated with a genetic abnormality. This abnormality has been identified, and a test is available. People at risk can be identified through genetic screening.
  • Once identified as carriers of the abnormal gene, these people require counseling and regular screening to detect precancerous and cancerous tumors.

HNPCC syndromes are sometimes linked to tumors in other parts of the body.

Other high risk factors for developing colon cancers include any one of the following:

The risk of colon cancer increases two to three times for people with a first-degree relative (parent or sibling) with colon cancer. The risk increases more if you have more than one affected family member, especially if the cancer was diagnosed at a young age.

Other factors that may affect your risk of developing a colon cancer include:

  • Diet: Whether diet plays a role in developing colon cancer remains under debate. The belief that a high-fiber, low-fat diet could help prevent colon cancer has been questioned. Studies do indicate that exercise and a diet rich in fruits and vegetables can help prevent colon cancer.
  • Obesity: Obesity has been identified as a risk factor for colon cancer.
  • Smoking: Cigarette smoking has been definitely linked to a higher risk for colon cancer.
  • Drug effects: Recent studies have suggested postmenopausal hormone estrogen replacement therapy may reduce colorectal cancer risk by one-third. Patients with a certain gene that codes for high levels of a hormone called 15-PGDH may have their risk of colorectal cancer reduced by one-half with the use of aspirin.

Causes of Hemorrhoids

Hemorrhoids are not arteries or veins, but instead are normal blood vessels called sinusoids that are located in the walls that surround the rectum and anus. When the venous pressure within these blood vessels increases, the hemorrhoids swell and dilate, because it is more difficult for blood to empty from them. This leads to the most common symptoms of bleeding and swelling.

Common situations that increase pressure within the hemorrhoidal blood vessels and lead to abnormalities include:

  • Colon cancers
  • Straining to have a bowel movement. This may be due to constipation or diarrhea.
  • Prolonged sitting, including on the toilet
  • Lack of exercise
  • Low fiber diet
  • Obesity
  • Pregnancy
  • Liver disease
  • Inflammatory bowel disease
  • Anal intercourse
  • Spinal cord injury

What Should I Do If I Have Signs and Symptoms of Colon Cancer or Hemorrhoids?

When to Call the Doctor for Colon Cancer Symptoms and Signs

If you have any of these symptoms call a doctor.

  • Bright red blood on the toilet paper, in the toilet bowl, or in your stool when you have a bowel movement
  • Change in the character or frequency of your bowel movements
  • Sensation of incomplete evacuation after a bowel movement
  • Unexplained or persistent abdominal pain or distension
  • Unexplained weight loss
  • Unexplained, persistent nausea or vomiting

If you have any of these symptoms, go to the nearest hospital Emergency Department.

  • Large amounts of bleeding from your rectum, especially if associated with sudden weakness or dizziness
  • Unexplained severe pain in your belly or pelvis (groin area)
  • Vomiting and inability to keep fluids down

When to Call the Doctor for Hemorrhoid Symptoms and Signs

Bleeding from the rectum or anus is never normal and although hemorrhoids are the most common reason to have blood in the stool. If you have rectal bleeding or blood in your stool, call a doctor. Other causes of rectal bleeding exist and can be serious. Inflammatory bowel disease and cancers of the colon can cause with rectal bleeding. Blood in the stool should never be ignored.

  • Seek medical care immediately if you take anticoagulation medications such as warfarin (Coumadin), dabigatran (Pradaxa), rivaroxiban (Xarelto), apixaban (Eliquis), clopidogrel (Plavix), prasugrel (Effient) or enoxaparin (Lovenox).
  • People who have associated symptoms such as lightheadedness and weakness may have significant blood loss and may require more urgent care.
  • Abdominal pain. Hemorrhoids do not cause abdominal pain.
  • Prolapsed hemorrhoids that cannot be pushed back through the anus.
  • Thrombosed external hemorrhoids may cause significant pain, and a doctor may need to remove the clot.


How to Get Rid of Hemorrhoids: Types, Causes and Treatments See Slideshow

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Rectal Cancer Symptoms vs. Hemorrhoids

Rectal cancer and hemorrhoids both cause rectal bleeding. Signs and symptoms of rectal cancer that do not occur with hemorrhoids are unexplained weight loss without dieting, bowel obstruction, anemia, constipation, and fatigue. Hemorrhoids can cause itching and pain around the anal area, which are not symptoms of rectal cancer. Rectal cancer can cause hemorrhoids due to prolonged sitting and straining while trying to have a bowel movement due to constipation or severe diarrhea. Hemorrhoids do not cause rectal cancer; however, they may be lead to colon cancer.

Reviewed on 8/10/2022
Image source: iStock Images

"Clinical presentation, diagnosis, and staging of colorectal cancer."

"Colorectal Cancer: Epidemiology, risk factors, and protective factors."

"Colorectal Cancer Statistics, 2017." American Cancer Society. May 1, 2017. <>.

"Colorectal Cancer: Types of Treatment." Cancer.Net. November 2018. <>.

"Overview of the management of primary colon cancer."

Rakel, R.E., and D. Rakel. Textbook of Family Medicine, 9th Edition. Saunders, 2015.

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