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Small Bowel

Small bowel cancer starts in the small intestine. The small intestine is the tube that connects your stomach to your large intestine. Most of your food is digested in your small intestine.
This information should not be used to diagnose yourself or in place of a doctor’s care.
Diagnosis & Staging

The small intestine is the largest part of your gastrointestinal (GI) tract.

The small intestine is about 2.5 cm (1 inch) across and about 4.5 to 6.0 m (15 – 20 feet) long. It has three parts:

  • Duodenum: connects to your stomach.
  • Jejunum: middle part.
  • Ileum: connects to your large intestine.

What are the signs and symptoms of small bowel cancer?

  • Pain or cramps in your abdomen (area below your ribs and above your pelvis). This is a common symptom.
  • Nausea or vomiting.
  • Weight loss you cannot explain.
  • Lump in your abdomen.
  • Blockage of your intestine.
  • Anemia (not enough iron in your blood).
  • Blood in your stool (poop) or dark stools (sometimes called melena).
  • Diarrhea (loose or runny stools).
  • Jaundice (when your skin or the whites of your eyes turn yellow).

Having one or more of these symptoms does not mean you have small bowel cancer. These symptoms can also happen because of other problems. For this reason, a person may not be diagnosed with small bowel cancer until the cancer is more advanced.

If you have any signs or symptoms that you are worried about, please talk to your family doctor or nurse practitioner.

How is small bowel cancer diagnosed?

Tests may help diagnose small bowel cancer include:

  • Blood tests.
  • Barium X-ray: used to look at the small intestine. You swallow a white, chalky liquid (barium mixed with water). After drinking the liquid, an x-ray technician takes x-rays of your small intestine. The barium is white on the x-ray image.
  • CT (computed tomography) scan.
  • Endoscopy: an endoscope is a flexible, lighted tube with a small video camera on the end. It is put into your body through your mouth. The endoscope then passes through your digestive system.  A doctor will use the camera to look at your small intestine.
  • Wireless capsule endoscopy: You swallow a small capsule that has a light and a very small camera. The capsule moves through your digestive system and takes thousands of pictures. The camera leaves your body during a bowel movement (going poop).
  • Laparotomy: a cut is made into your abdomen so that a doctor can use a camera (laparoscope) to look at your organs.

For more information on tests used to diagnose cancer: BC Cancer Library screening and diagnosis pathfinder.

What are the types of small bowel cancer?

  • Adenocarcinoma: the most common type of small bowel cancer. It starts in the glandular cells in the lining of the small intestine.
  • Carcinoid tumours: 30% (30 out of 100) of small bowel cancers are carcinoid tumours.  They start in hormone-producing (endocrine) cells in the lining of the small intestine. These can be fast or slow growing cancers.
  • Lymphoma: 14% (14 out of 100) of small bowel cancers are lymphomas. Most are non-Hodgkin's lymphomas.
  • Sarcoma: 11% (11 out of 100) of small intestine cancers are sarcomas.  
    • Types of sarcomas
      • liposarcomas start in the fat cells.
      • angiosarcomas start in the blood vessels.
      • neurofibrosarcomas start in the nerves.
      • leiomyosarcomas start in the smooth muscles of the small intestine.
  • Gastrointestinal Stromal Tumour (GIST):  GISTs start in cells that are part of the autonomic nervous system in the wall of the small intestine. About 50 people are diagnosed with GIST in B.C. each year. It is very rare.

What are the stages of small bowel cancer?

Staging describes the cancer. Staging is based on how much cancer is in the body, where it was first diagnosed, if the cancer has spread and where it has spread to.

The stage of the cancer can help your health care team plan your treatment. It can also tell them how your cancer might respond to treatment and the chance that your cancer may come back (recur). 

Small bowel cancer staging

  • Stage 0: Tumour has not spread through the inner layers of your small intestine.
  • Stage 1: Tumour has grown through the inner layers of your small intestine but has not spread into nearby tissue or lymph nodes. 
  • Stage 2: Tumour has spread through the entire wall of your small intestine but has not spread to the nearby lymph nodes. 
  • Stage 3: The cancer has spread to nearby lymph nodes but has not spread to other parts of your body. 
  • Stage 4: The cancer has spread to other parts of your body.

For more information on staging: About Cancer 

What are the grades of small bowel cancer?

The grade of the cancer describes how different the cancer cells look from normal cells and how fast the cancer cells are growing.  A pathologist will give the cancer a grade after looking at the cells under a microscope.

Small bowel cancer can be grade 1, 2, 3 or 4. The lower the number, the lower the grade. 

Low grade: cells are abnormal but look a lot like normal cells.  Low grade cancers usually grow slowly and are less likely to spread.

High grade: cells are abnormal and do not look like normal cells. High grade cancers usually grow more quickly and are more likely to spread. 

The grade of the cancer can help your health care team plan your treatment. 


What is the treatment for small bowel cancer?

Cancer treatment may be different for each person. It depends on your particular cancer. Your treatment may be different from what is listed here.

Here is information on how we treat the most common types of small bowel cancer:


  • Usually removed by surgery if it has not spread to another part of your body.
  • If the cancer cannot be removed, you may have surgery to help with a blockage or to stop bleeding.
  • After surgery to remove the cancer, you may have systemic therapy (chemotherapy). This is called adjuvant systemic therapy. It may increase the chance of cure for people with localized cancer (cancer that has not spread). 
  • If your cancer has metastasized (spread to other parts of your body), systemic therapy is the main treatment. It tries to control the cancer for as long as possible. It cannot cure the cancer.


  • Surgery is an option if the cancer has not spread or if a large part of the cancer can be removed. It is also sometimes used if the cancer is blocking food from moving through your intestine.
  • These cancers can produce hormones. You may need medications to help with the side effects from these hormones.
  • If the cancer has spread from where it started, you may need targeted medications or a special type of targeted radiation given intravenously (a needle attached to a tube is put into your vein to give the treatment).

What is the follow-up after treatment?

  • Follow-up testing and appointments are based on your type of cancer.
  • There are no specific follow-up guidelines for small bowel cancer. 
  • People who had small bowel adenocarcinoma may have a higher risk of second cancers in the colon, ovary, endometrium and rectum.  If you have any symptoms you are worried about, please talk to your health care team.
  • After treatment, you may return to the care of your family doctor or specialist for regular follow-up. If you do not have a family doctor, please talk to your BC Cancer health care team.
  • Life after Cancer page has information on issues that cancer survivors may face.

More Information

What causes small bowel cancer and who gets it?

Cancer of the small bowel is rare. About 60% (60 out of 100) of people who get small intestine cancer are men. [See note below, Statistics]

These are some of the risk factors for this cancer. Not all of these risk factors may cause this cancer, but they may help the cancer start growing. 

  • Being over the age of 45.
  • Eating large amounts of:
    • Animal proteins and animal fat.
    • Refined carbohydrates.
    • Red meat.
    • Salt-cured or smoked foods. 
  • An infection with Helicobacter pylori.
  • Having Crohn's Disease or Celiac Disease.
  • Radiation therapy for cancer of the cervix.
  • People with inherited disorders such as: 
    • Familial Adenomatous Polyposis (FAP)
    • Hereditary Nonpolyposis Colorectal Cancer (HNPCC)
    • Peutz-Jeghers Syndrome (PJS)
    • Cystic Fibrosis (CF) 

Statistics on small bowel cancer 

Note:  Available statistics do not have information about the inclusion of transgender and gender diverse participants. It is unknown how these statistics apply to transgender and gender diverse people.  Patients are advised to speak with their primary care provider or specialists about their individual considerations and recommendations.

Can I help prevent small bowel cancer?

  • Eating healthy, nutritious foods can lower your cancer risk. 
  • Eat a gluten-free diet if you have celiac disease. This seems to lower the risk of small bowel cancer.
  • Do not eat large amounts of:
    • Animal proteins and animal fats.
    • Refined carbohydrates.
    • Red meat.
    • Salt-cured or smoked foods.

Is there screening for small bowel cancer?

There is no screening program for small bowel cancer.

People who are at higher risk of developing small bowel cancer, especially people with Familial Adenomatous Polyposis (FAP), may need to be tested.  There is more information about genetic testing on our Hereditary Cancer Program page.

Where can I find more information?

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