Rectal bleeding is the most common sign or symptom that both rectal cancer and hemorrhoids share. Other shared symptoms include blood mixed with stool, a change in bowel habits (for example, more gas, change in stool size and or diarrhea), tenesmus (feeling like you need to have a bowel movement), and discomfort and/or pain during bowel movements.
There are a few key symptoms to look out for if you think you might have rectal cancer, including unexplained weight loss, bowel obstruction, anemia, and fatigue. These symptoms are not usually seen with hemorrhoids.
Hemorrhoids can cause pruritus (itching) in the rectal and/or anal area, while rectal cancers usually do not. Many hemorrhoids can be palpated or seen during a physical exam and are usually easy to diagnose. Rectal cancers are diagnosed by biopsy.
Rectal cancers are abnormal, uncontrolled cells that may metastasize to other organs. Hemorrhoids, on the other hand, are swollen blood vessels that are located only in the rectal area. They do not metastasize. Situations that increase abdominal pressure can be a risk factor for developing hemorrhoids.
For example, straining for bowel movements, prolonged sitting, or having a low fiber diet can lead to hemorrhoids. On the other hand, risk factors for developing rectal cancer include things like aging, smoking, and having a family history of cancer.
Rectal Cancer
The primary function of the rectum is to store stool before evacuation. The rectum has three layers: the mucosa, the muscularis propria, and the mesorectum. The mucosa is the inner layer that is lined with glands that secrete mucus. The muscularis propria is the middle layer that is composed of muscles that help the rectum keep its shape and contract to expel stool. The mesorectum is the outer layer of fatty tissue that surrounds the rectum.
The rectum also has surrounding lymph nodes, which are commonly called regional lymph nodes. These nodes are an important part of the immune system. Their job is to help protect the body by keeping an eye out for harmful materials, like viruses and bacteria. Lymph nodes are located around every organ in the body, including the rectum.
The American Cancer Society (ACS) estimates that in 2017, 95,520 new cases of colon cancer and 39,910 new cases of rectal cancer will occur. Males are more likely than females to develop rectal cancer. The most common type of rectal cancer is adenocarcinoma, which is a cancer arising from the mucosa. Cancer cells can also spread from the rectum to the lymph nodes on their way to other parts of the body.
Just like with colon cancer, the prognosis and treatment of rectal cancer depends on how deeply the cancer has invaded the rectal wall and surrounding lymph nodes (its stage, or extent of spread). However, even though the rectum is part of the colon, the location of the rectum in the pelvis creates additional challenges in treatment when compared with colon cancer.
Hemorrhoids
Hemorrhoids are enlarged and swollen blood vessels located in the lower part of the rectum and anus. The blood vessels become swollen due to increased pressure within them. They are usually caused by increased pressure within the lower abdomen. Some potential causes include straining at the time of bowel movement.
Internal hemorrhoids are found on the inside lining of the rectum and normally cannot be felt unless they prolapse and push through the anal opening, causing pain and itching. External hemorrhoids are found beneath the skin on the outer aspect of the anus. Symptoms may include bleeding during a bowel movement and a mass or fullness that can be felt at the anal opening.
Cause and Symptoms
Rectal cancer usually develops over several years. It starts as a growth called a polyp, which may turn into cancer and grow into the rectum. The actual cause of rectal cancer is unclear, but risk factors include increasing age, smoking, family history of colon or rectal cancer, high-fat diet, personal or family history of polyps or colorectal cancer, and inflammatory bowel disease.
Family history is one way that doctors can determine if someone is at risk for rectal cancer. If there is a family history of colorectal cancer in a first-degree relative, then that person should start having endoscopies 10 years before the age that the relative was diagnosed with cancer, or at age 50, whichever comes first.
However, even if there is no family history of colorectal cancer, it’s still important to get screened for rectal cancer regularly. Screening for rectal cancer is the best way to prevent it.
Hemorrhoids are actually a type of blood vessel called sinusoids, which are located in the walls around the rectum and anus. When the pressure in these vessels increases, it causes the hemorrhoids to swell and dilate. This can cause common symptoms like bleeding and swelling.
There are a lot of things that can put pressure on the blood vessels in and around your anus, which can lead to all sorts of problems. Things like straining to much because of constipation or diarrhea, sitting for a long time (including on the toilet), being obese, being pregnant, and having anal sex can all cause issues. If you want to avoid these problems, it’s important to exercise, eat a high-fiber diet, and take breaks often if you sit for long periods of time.
Diagnosing Hemorrhoids vs. Cancer
Hemorrhoids can typically be identified by a simple rectal exam and medical history by a doctor. They might suggest a biopsy to check for anal cancer if they see an odd development that is not a hemorrhage.
On the other hand, colon cancer is more challenging to diagnose. This is due to the fact that cancer markers do not always indicate whether a cancer is present or not. Therefore, based on symptoms, the doctor might also suggest testing. They might inquire as to whether someone has bleeding but no hemorrhoids or whether receiving therapy for hemorrhoids does not make their symptoms go away. They might also run tests on the blood to check for cancer markers or suggest a colonoscopy to check for growths. While the patient is unconscious or under sedation, a small, flexible tube is inserted during a colonoscopy into the rectum. If a growth is discovered, the doctor might suggest a biopsy or have it examined in a lab.
Key Takeaway
Rectal cancers are abnormal, uncontrolled cells that may spread to other organs. Hemorrhoids, on the other hand, are swollen blood vessels that are located only in the rectal area and will not spread.
