Small Bowel Cancer: The Basics

Author: OncoLink Team
Content Contributor: Katherine Okonak, MSW, LSW
Last Reviewed: February 16, 2024

The small bowel (small intestine) is the part of the digestive tract that connects the stomach to the large bowel (colon). There are three parts to the small bowel: the duodenum, the jejunum, and the ileum. Small bowel cancer is caused by small bowel cells growing out of control. As the number of cells grow, they form a tumor. Types of small bowel cancer are:

  • Adenocarcinoma: usually starts in the lining or inside layer of the bowel, usually in the duodenum.
  • Sarcoma: usually starts in the muscle wall in the ileum.
  • Carcinoid: a type of neuroendocrine tumor in the ileum.
  • Lymphoma: starts in the lymph tissue usually in the jejunum.

Small bowel cancer that has spread from the small bowel to another part of the body is called metastatic cancer.


Risk factors for small bowel cancer are:

  • Smoking and drinking alcohol.
  • Celiac or Crohn’s disease.
  • Having had colon cancer.
  • Genetic mutations (changes).

Signs of Small Bowel Cancer

The signs of small bowel cancer are not very specific but can include:

  • Belly pain.
  • Blood in the stool (bright red or dark, tarry, and black).
  • Losing weight.
  • Diarrhea.
  • Yellowing of the skin and eyes (jaundice).
  • Feeling weak or tired.

Diagnosis of Small Bowel Cancer

When your healthcare providers think you may have small bowel cancer, they will order tests. Here are some of the tests:

Staging Small Bowel Cancer

To guide treatment, small bowel cancer is "staged." The stage is based on:

  • Size and location of the tumor.
  • If cancer cells are in the lymph nodes.
  • If cancer cells are in other parts of the body.

Stages range from stage I (smallest, most confined tumors) to stage IV (tumors that have spread to other parts of the body, also called metastatic cancer). The stage and type of small bowel cancer will guide your treatment plan.


Treatments often used are:

  • Surgery can be used to take out the tumor and to take out parts of organs that have cancer in them.
  • Radiation, the use of high energy x-rays to kill cancer cells, can be used after surgery or to treat cancer that has spread.
  • Chemotherapy, the use of medications to kill cancer cells, can be given by itself or with surgery or radiation.

This article is a basic guide to small bowel cancer. You can learn more about your type of small bowel cancer and treatment by using the links below.

Small Bowel Cancer: Staging and Treatment

Surgical Procedures: Small Bowel Resection


SEER Stat Fact Sheets. Small Intestine Cancer.

American Cancer Society. Small Intestine Cancer.

American Cancer Society. (2018). Small Intestine Cancer (Adenocarcinoma). Retrieved from

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