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Signs and Symptoms of Small Intestine Cancer (Adenocarcinoma)

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(Note: This information is about small intestine cancers called adenocarcinomas. To learn about other types of cancer that can start in the small intestine, see Gastrointestinal Carcinoid Tumors, Gastrointestinal Stromal Tumors, or Non-Hodgkin Lymphoma.)

The symptoms of small intestine cancers are often vague and can have other, more common causes. Unfortunately, this means that it’s often at least several months from the time symptoms start until the cancer is diagnosed.

Some of the more common symptoms of small intestine cancer are:

  • Pain in the belly (abdomen)
  • Nausea and vomiting
  • Weight loss (without trying)
  • Weakness and feeling tired (fatigue)
  • Dark-colored stools (from bleeding into the intestine)
  • Low red blood cell counts (anemia)
  • Yellowing of the skin and eyes (jaundice)

Often, the first symptom is pain in the stomach area. This pain is often crampy and may not be constant. For example, it may start or get worse after you eat.

As the tumor gets larger, it can slow the passage of digested food through the intestine. This can lead to increased pain. If the tumor gets large enough, it can cause an obstruction, in which the intestine is completely blocked and nothing can move through. This leads to pain with severe nausea and vomiting.

Rarely, a cancer will cause a hole (perforation) to form in the wall of the intestine. This hole lets the contents of the intestine spill into the abdomen. Symptoms of perforation can include sudden severe pain, nausea, and vomiting.

Sometimes a tumor will start bleeding into the intestine. If the bleeding is slow, it could lead to a low red blood cell count (anemia) over time. Symptoms of anemia include weakness and fatigue. If the bleeding is rapid, the stool can become black and tarry from digested blood, and the person may feel lightheaded or even pass out.

Less often, a tumor in the duodenum (the first part of the small intestine) can cause jaundice. This can happen if the tumor blocks the bile duct, which can prevent the contents from the liver from entering the intestine.

These problems are more often caused by things other than cancer. Still, if you have any of them, especially if they don't go away or are getting worse, have them checked by your doctor to find the cause so it can be treated, if needed.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.

Chamberlain RS, Krishnaraj M, Shah SA. Chapter 54: Cancer of the Small Bowel. In: DeVita VT, Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg’s Cancer: Principles and Practice of Oncology. 10th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2015.

Doyon L, Greenstein A, Greenstein A. Chapter 76: Cancer of the Small Bowel. In: Niederhuber JE, Armitage JO, Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 5th ed. Philadelphia, Pa: Elsevier; 2014.

Overman MJ, Kunitake H. Epidemiology, clinical features, and types of small bowel neoplasms. UpToDate. Accessed at on January 4, 2018.

Last Revised: February 8, 2018

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