The rectum is the last several inches of the large intestine. Rectal cancer starts in the lining of the rectum (rectal mucosa).
Rectal cancer is cancer that begins in the rectum. The rectum is the last several inches of the large intestine. It starts at the end of the final segment of your colon and ends when it reaches the short, narrow passage leading to the anus.
Cancer inside the rectum (rectal cancer) and cancer inside the colon (colon cancer) are often referred to together as "colorectal cancer."
While rectal and colon cancers are similar in many ways, their treatments are quite different. This is mainly because the rectum sits in a tight space, barely separated from other organs and structures. The tight space can make surgery to remove rectal cancer complex.
In the past, long-term survival was uncommon for people with rectal cancer, even after extensive treatment. Thanks to treatment advances over the last few decades, rectal cancer survival rates have greatly improved.
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Signs and symptoms of rectal cancer include:
- A change in bowel habits, such as diarrhea, constipation or more-frequent bowel movements
- Dark maroon or bright red blood in stool
- Narrow stool
- A feeling that your bowel doesn't empty completely
- Abdominal pain
- Unexplained weight loss
- Weakness or fatigue
When to see a doctor
Make an appointment with your doctor if you have any persistent symptoms that worry you.
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Rectal cancer begins when healthy cells in the rectum develop changes (mutations) in their DNA. A cell's DNA contains the instructions that tell a cell what to do.
The changes tell the cells to grow uncontrollably and to continue living after healthy cells would die. The accumulating cells can form a tumor. With time, the cancer cells can grow to invade and destroy healthy tissue nearby. And cancerous cells can break away and travel (metastasize) to other parts of the body.
For most rectal cancers, it's not clear what causes the mutations that cause the cancer to form.
Inherited gene mutations that increase the risk of colon and rectal cancer
In some families, gene mutations passed from parents to children increase the risk of colorectal cancer. These mutations are involved in only a small percentage of rectal cancers. Some genes linked to colorectal cancer increase the risk of developing the disease, but they don't make it inevitable.
Two well-defined genetic colorectal cancer syndromes are:
- Lynch syndrome. Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer (HNPCC), increases the risk of colon cancer and other cancers. People with Lynch syndrome tend to develop colon cancer before age 50.
- Familial adenomatous polyposis (FAP). FAP is a rare disorder that causes thousands of polyps in the lining of your colon and rectum. People with untreated FAP have a significantly increased risk of developing colon or rectal cancer before age 40.
Genetic testing can detect these and other, rarer inherited colorectal cancer syndromes. If you're concerned about your family history of colon cancer, talk to your doctor about whether your family history suggests you have a risk of these conditions.
Factors that may increase the risk of rectal cancer are the same as those that increase the risk of colon cancer. Colorectal cancer risk factors include:
- Older age. Colorectal cancer can be diagnosed at any age, but most people with this type of cancer are older than 50. The rates of colorectal cancer in people younger than 50 have been increasing, but doctors aren't sure why.
- African-American descent. People of African ancestry born in the United States have a greater risk of colorectal cancer than do people of European ancestry.
- A personal history of colorectal cancer or polyps. Your risk of colorectal cancer is higher if you've already had rectal cancer, colon cancer or adenomatous polyps.
- Inflammatory bowel disease. Chronic inflammatory diseases of the colon and rectum, such as ulcerative colitis and Crohn's disease, increase your risk of colorectal cancer.
- Inherited syndromes that increase rectal cancer risk. Genetic syndromes passed through generations of your family can increase your risk of colon and rectal cancer, including FAP and Lynch syndrome.
- Family history of colorectal cancer. You're more likely to develop colorectal cancer if you have a parent, sibling or child with colon or rectal cancer.
- Eating a diet low in vegetables. Colorectal cancer may be associated with a diet low in vegetables and high in red meat, particularly when the meat is charred or well done.
- Too little exercise. If you're inactive, you're more likely to develop colorectal cancer. Getting regular physical activity may reduce your risk of cancer.
- Diabetes. People with poorly controlled type 2 diabetes may have an increased risk of colorectal cancer.
- Obesity. Obese people have an increased risk of colorectal cancer when compared with people considered at a healthy weight.
- Smoking. People who smoke may have an increased risk of colorectal cancer.
- Drinking alcohol. Regularly drinking more than three alcoholic beverages a week may increase your risk of colorectal cancer.
- Radiation therapy for previous cancer. Radiation therapy directed at the abdomen to treat previous cancers may increase the risk of colorectal cancer.
To reduce your risk of colorectal cancer, consider trying to:
Talk to your doctor about cancer screening. Colorectal cancer screening reduces the risk of cancer by identifying precancerous polyps in the colon and rectum that could develop into cancer. Ask your doctor when you should begin screening. Most medical organizations recommend starting screening around age 45, or earlier if you have risk factors for colorectal cancer.
Several screening options exist — each with its own benefits and drawbacks. Talk about your options with your doctor, and together you can decide which tests are appropriate for you.
- Exercise most days of the week. Try to get at least 30 minutes of exercise on most days. If you've been inactive, start slowly and build up gradually to 30 minutes. Also, talk to your doctor before beginning any exercise program.
- Eat a variety of fruits, vegetables and whole grains. Fruits, vegetables and whole grains contain vitamins, minerals, fiber and antioxidants, which may play a role in cancer prevention. Choose a variety of fruits and vegetables so that you get an array of vitamins and nutrients.
- Maintain a healthy weight. If you're at a healthy weight, maintain it by exercising regularly and choosing a healthy diet. If you're overweight, work to lose weight slowly by increasing exercise and reducing the number of calories you eat.
- Stop smoking. If you smoke, stop. If you're having trouble quitting, talk to your doctor about options. Medications and counseling may help.
- Drink alcohol in moderation, if at all. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women and up to two drinks a day for men.
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- A change in bowel habits, such as diarrhea, constipation or more-frequent bowel movements.
- Dark maroon or bright red blood in stool.
- Narrow stool.
- A feeling that your bowel doesn't empty completely.
- Abdominal pain.
- Unexplained weight loss.
- Weakness or fatigue.
The most common symptoms of rectal cancer are a change in bowel habits, such as constipation or diarrhea, narrow shaped stools, or blood in your stool. You may also have pelvic or lower abdominal pain, unexplained weight loss, or feel tired all the time. Other common health problems can cause the same symptoms.How painful is rectal cancer? ›
Cancer of the rectum should be considered whenever there is rectal bleeding, even if other causes such as hemorrhoids are present. A person may feel as if there is incomplete evacuation. There usually is no pain until later stages of the condition.Is rectal cancer curable? ›
Rectal cancer is a disease in which cancer cells develop in the rectum. Signs of rectal cancer include diarrhea, constipation or blood in your poop. Treatments include surgery, chemotherapy and radiation therapy. Rectal cancer is curable, especially when detected early through screening methods like colonoscopy.Does rectal cancer spread fast? ›
In most cases, colon and rectal cancers develop slowly over many years. Most of these cancers begin as a growth of tissue called a polyp in the inner lining of the colon or rectum. Usually polyps bulge into the colon or rectum; some are flat.What is early stage rectal cancer? ›
Stage I rectal cancers have grown into deeper layers of the rectal wall but have not spread outside the rectum itself. This stage includes cancers that were part of a polyp. If the polyp is removed completely during colonoscopy, with no cancer in the edges, no other treatment may be needed.Which is worse colon or rectal cancer? ›
Conclusion. This was a population-based study. The prognosis of rectal cancer was not worse than that of colon cancer. Local advanced colorectal cancer had a poorer prognosis than local regional lymph node metastasis.How long does rectal cancer take to develop? ›
In two more recent studies, the total median time between symptom onset and diagnosis of rectal cancer was found to be around three months in a group of 180 patients11 and around four months in a sample of 66 patients.What age does rectal cancer occur? ›
Colorectal cancer can occur in young adults and teenagers, but the majority of colorectal cancers occur in people older than 50. For colon cancer, the average age at the time of diagnosis for men is 68 and for women is 72. For rectal cancer, it is age 63 for both men and women.How long can you live with rectal cancer? ›
|SEER stage||5-year relative survival rate|
|All SEER stages combined||67%|
For rectal cancer, the overall 5-year survival rate for people is 67%. If the cancer is diagnosed at a localized stage, the survival rate is 90%. If the cancer has spread to surrounding tissues or organs and/or the regional lymph nodes, the 5-year survival rate is 73%.Where is the first place rectal cancer spreads to? ›
Colorectal cancer usually spreads to the liver. It can also spread to the lungs, the lining of the abdomen, the ovaries, the brain, and other organs. Recent advances in treatment have improved the outlook for people with metastatic rectal cancer, including stage IV cancer.What are the signs of end stage rectal cancer? ›
Drowsiness, increased sleep, and/or unresponsiveness (caused by changes in the patient's metabolism). Confusion about time, place, and/or identity of loved ones; restlessness; visions of people and places that are not present; pulling at bed linens or clothing (caused in part by changes in the patient's metabolism).How do you get rectal cancer? ›
You're more likely to develop colorectal cancer if you have a parent, sibling or child with colon or rectal cancer. Eating a diet low in vegetables. Colorectal cancer may be associated with a diet low in vegetables and high in red meat, particularly when the meat is charred or well done. Too little exercise.What does cancerous poop look like? ›
Blood from higher up in the bowel doesn't look bright red. It goes dark red or black and can make your poo look like tar. This type of bleeding can be a sign of cancer higher up the bowel.What does cancerous poop look like? ›
Blood from higher up in the bowel doesn't look bright red. It goes dark red or black and can make your poo look like tar. This type of bleeding can be a sign of cancer higher up the bowel.What are the early warning signs of bowel cancer? ›
- Bleeding. Watch out for bright red rectal bleeding or dark, tarry stools, which could indicate the presence of blood.
- Stomach pain. Look for persistent abdominal pain, discomfort, or bloating.
- Change in bowel habits. ...
- Tenesmus. ...
- Unexplained weight loss. ...
In two more recent studies, the total median time between symptom onset and diagnosis of rectal cancer was found to be around three months in a group of 180 patients11 and around four months in a sample of 66 patients.Does rectal cancer feel like hemorrhoids? ›
The main warning signs of anal cancer are rectal pain, itching and bleeding, as well as changes in bowel movements, such as unusually narrow stools. Hemorrhoids, which are painful clusters of inflamed veins in the rectum and anus, can produce many of the same symptoms as anal cancer.Where do you feel colon pain? ›
Sudden severe abdominal pain, especially in the lower abdomen and on the left side, is common with colon spasms. The pain can vary in its intensity with each spasm. Gas or bloating. These signs may occur any time of the day, regardless of diet.
The spontaneous expulsion per rectum of a polyp is rare, and the literature regarding such cases is limited. There have been several reported cases of rectal expulsion of lipomas [22-29]. With an incidence of 0.035-4.4%, lipomas are the second-most common benign tumors of the colon .When should I be worried about blood when I wipe? ›
If you see blood in stool or on toilet paper after a bowel movement, take note of how much blood there is. If there is a significant amount or continuous bleeding, see your doctor as soon as possible. You should also seek help if your stool appears black, tarry or maroon in color.What is the most common symptom of bowel cancer? ›
The 3 main symptoms of bowel cancer are: persistent blood in your poo – that happens for no obvious reason or is associated with a change in bowel habit. a persistent change in your bowel habit – which is usually having to poo more and your poo may also become more runny.Can you have bowel cancer for years without knowing? ›
Colon cancer is typically slow-growing, starting as a benign polyp that eventually becomes malignant. This process may occur over many years without producing any symptoms. Once colon cancer has developed, it may still be years before it is detected.Can a blood test detect bowel cancer? ›
The most common tumor marker for colorectal cancer is carcinoembryonic antigen (CEA). Blood tests for this tumor marker can sometimes suggest someone might have colorectal cancer, but they can't be used alone to screen for or diagnose cancer.Can you survive rectal cancer? ›
For rectal cancer, the overall 5-year survival rate for people is 67%. If the cancer is diagnosed at a localized stage, the survival rate is 90%. If the cancer has spread to surrounding tissues or organs and/or the regional lymph nodes, the 5-year survival rate is 73%.Which is worse colon or rectal cancer? ›
Conclusion. This was a population-based study. The prognosis of rectal cancer was not worse than that of colon cancer. Local advanced colorectal cancer had a poorer prognosis than local regional lymph node metastasis.What is the life expectancy of someone with rectal cancer? ›
5-year relative survival rates for rectal cancer.
|SEER stage||5-year relative survival rate|
|All SEER stages combined||67%|
A hard growth tends to suggest anal cancer while a squishy swelling suggests hemorrhoids. For more information on what they look and feel like, see this resource on hemorrhoids.