How to Detect Rectal Cancer

Medically reviewed by Gary Hoffman, MD

Last Updated: January 15, 2021 References

Colorectal cancer is the second leading cause of cancer deaths in men and women combined, as it can be difficult to detect without the proper tests. But when this cancer is caught in the early stage, the recovery rate can be as high as 90%.^{[1]
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Trustworthy Source
American Cancer Society
Nonprofit devoted to promoting cancer research, education, and support
Go to source} You can detect rectal cancer by watching for symptoms and signs of the disease and by getting screening tests done by your doctor. Your doctor can then diagnose your condition and if you have rectal cancer, can recommend immediate treatments so you recover successfully.

Method 1

Method 1 of 3:

Checking for Symptoms

1
Notice if you have chronic diarrhea or constipation. One of the most common symptoms of colorectal cancer is irregular bowel movements or being unable to control your bowels. You may also have difficulty emptying your bowels completely and experience discomfort when you have a bowel movement.^{[2]
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Research source}
2
Check if you have bloody stool. If the blood appears bright red or very dark, this could be a sign of a serious issue like rectal cancer. You may also have stools that appear narrower than usual or have a different size or shape than normal.^{[3]
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Research source}
- This is one of the most common early warning signs of rectal cancer.^{[4]
  X
  Expert Source
  
  Gary Hoffman, MD
  Colorectal Surgeon
  Expert Interview. 29 December 2020.}
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3
Notice if you have pain in your rectum or abdominal area. You may also experience gas pains or stomach cramps and feel bloated or full all the time, even if you have not eaten recently.^{[5]
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4
Check if you have low appetite or feel fatigued all the time. Your appetite may be low and you may experience weight loss because you are not eating enough. You may also feel tired often and have low energy.^{[6]
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- If you have several of these symptoms or your symptoms become severe, go see your doctor so you can get screened for rectal cancer right away.

Method 2

Method 2 of 3:

Getting Screening Tests

1
Get a fecal occult blood test (FOBT). This test requires you to provide a stool sample so your doctor can test for small amounts of blood in your feces. Depending on which type of FOBT you undergo, you may need to avoid certain foods before getting the test. Your doctor can outline the details of the test and any steps you need to take before you provide a sample.^{[7]
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National Cancer Institute
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- Your sample will then be sent to a lab for testing and your doctor will receive the results of the test in a few weeks.
2
Have a digital rectal exam (DRE). For this exam, your doctor will exam your rectum and abdominal for any lumps. If they notice any lumps, they may perform a more detailed test like a sigmoidoscopy or a colonoscopy.^{[8]
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National Health Service (UK)
Public healthcare system of the UK
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- You may find getting this test done a bit uncomfortable but your doctor should walk you through the exam and make you feel at ease. The DRE usually takes no longer than a few minutes to complete.
- Sometimes, you might not have any symptoms of rectal cancer at all. That's why it's important to have a routine colonoscopy done annually after you turn 45.^{[9]
  X
  Expert Source
  
  Gary Hoffman, MD
  Colorectal Surgeon
  Expert Interview. 29 December 2020.}
3
Allow your doctor to do a sigmoidoscopy. This procedure uses a sigmoidoscope, a flexible tube with a lens, to look into your rectum and colon lining. The sigmoidoscope will need to be inserted into your anus, so your lower colon must be cleared of stool beforehand.^{[10]
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National Cancer Institute
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- You are not usually sedated when undergoing this procedure, though you can ask your doctor to do so if you’d prefer.
4
Let your doctor perform a colonoscopy. A colonoscopy is done by inserting a colonoscope, a flexible tube with a lens, into your anus so your doctor can check your rectum and colon. Your doctor can also remove any abnormal growths in your colon, upper colon, or rectum for further testing.^{[11]
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National Cancer Institute
An agency in the National Institutes of Health focused on cancer research and patient support
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- You are usually under sedation during the colonoscopy to ensure you do not experience any pain or discomfort.
- Your doctor will recommend that you do a deep cleanse of your colon before the test. Make sure you prepare properly for the colonoscopy so it goes well.
5
Try a virtual colonoscopy for a less invasive option. A virtual colonoscopy uses x-ray equipment and a CT scanner to take pictures of your colon and rectum form outside your body. This screening method may be a good option if you’d do not want have to have a standard colonoscopy or you cannot have one due to other health issues.^{[12]
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National Cancer Institute
An agency in the National Institutes of Health focused on cancer research and patient support
Go to source}
- You will still need to do a thorough cleanse of your colon before the test for it to work.
- If any abnormal growths are found during the virtual colonoscopy, your doctor will have to perform a standard one to remove them.
- Some healthcare providers do not cover the cost of a virtual colonoscopy. Check with your insurance provider before you get this test done if you are worried about the cost.
6
Get a double-contrast barium enema if you cannot get a colonoscopy. This screening option requires you to take an enema with a barium solution. The solution will help to outline your colon and rectum when you undergo an x-ray. This option is not as detailed as a colonoscopy but it can be ideal if you have medical issues that prevent you from having a colonoscopy.^{[13]
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Trustworthy Source
National Cancer Institute
An agency in the National Institutes of Health focused on cancer research and patient support
Go to source}

Method 3

Method 3 of 3:

Diagnosing Rectal Cancer

1
Discuss your test results with your doctor. Once you have been screened for rectal cancer, your doctor will analyze your test results and let you know if you test positive for the cancer. Alternatively, you may have polyps, or abnormal cells, on your rectum that are not cancerous but may need to be observed more closely in the event they do become cancerous.
- Rectal cancer that is caught early has a high recovery rate, so the sooner you know you have it, the more effective the treatment will be.
2
Determine the stage of your rectal cancer, if you test positive. There are 4 stages of rectal cancer. Early stage rectal cancer has a higher survival rate than late-stage rectal cancer. The stages are:^{[14]
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National Health Service (UK)
Public healthcare system of the UK
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- Stage 1, where the cancer is just within the lining of your rectum.
- Stage 2, where the cancer has spread to the surface covering your rectum or nearby organs.
- Stage 3, where the cancer has spread into your lymph nodes.
- Stage 4, where the cancer has spread to other areas of your body, such as your liver.
- The stage of your rectal cancer will then dictate your treatment options. Most rectal cancers can be treated effectively with chemotherapy and medication.
3
Get screened for rectal cancer as necessary. If you do not test positive for rectal cancer, you should still get screened at intervals recommended by your doctor, especially if you are between 50 and 75. This cancer is highly treatable if caught early so regular screening is the best way to detect it and prevent it from becoming life-threatening.^{[15]
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- Your doctor can create a schedule for screenings for rectal cancer so you can stay on top of them and stay healthy. While some people may need a screening every few years, others may only need them once a decade. Your doctor will help you decide what's right for you.^{[16]
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  Trustworthy Source
  American Academy of Family Physicians
  Organization devoted to improving the health of patients, families, and communities
  Go to source}

Expert Q&A
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Question

Can you feel rectal cancer?

Gary Hoffman, MD
Colorectal Surgeon
Dr. Gary Hoffman is a board certified Colorectal Surgeon and the Clinical Chief of the Division of Colon and Rectal Surgery at Cedars Sinai Medical Center. With over 35 years of experience, Dr. Hoffman has helped to advance laparoscopic and robotic surgery for the treatment of colon and rectal cancer. Dr. Hoffman holds a BS from the University of California, Irvine, and a Doctor of Medicine (MD) from Vanderbilt University. He completed his surgical internship at Los Angeles County-USC Medical Center and his surgical residency at Louisiana State University-Charity Hospital of New Orleans Medical Center. Dr. Hoffman is an Attending Surgeon in the Division of General Surgery and Colon and Rectal Surgery at Cedars Sinai Medical Center. He is also an Associate Clinical Professor of Surgery at The David Geffen School of Medicine, University of California, Los Angeles. Dr. Hoffman is a member of The American Society of Colon and Rectal Surgeons, The Southern California Society of Colon and Rectal Surgeons, The American College of Surgeons, and The American Medical Association.

Gary Hoffman, MD

Colorectal Surgeon

Expert Answer

Support wikiHow by unlocking this expert answer.

A lot of patients go in for a checkup because they're having rectal bleeding or painful bowel movements. However, there are also a lot of people who don't have any symptoms at all, which is why it's important to have a routine colonoscopy done after you turn 45, or sooner if you have a family history of rectal cancer.