Gastrointestinal Cancer Causes and Symptoms

Gastrointestinal cancer is a term that encompasses a group of cancers that affect the gastrointestinal tract. Types of gastrointestinal cancer include:

Doctor and Patient, Abdomen Palpation
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Causes and Risk Factors

We don't know the cause of many types of gastrointestinal cancer, but risk factors for gastrointestinal cancer vary among the different types. They include:

  • Smoking
  • Excessive alcohol consumption
  • Increasing age
  • Diet high in animal fat
  • Diet containing high amounts of salted, cured, or poorly preserved foods
  • Chronic pancreatitis
  • Obesity

Please note that there are many other risk factors that are disease-specific that are not listed.


Symptoms of gastrointestinal cancer vary, depending on the type of cancer. Symptoms may include:

  • Abdominal pain, tenderness, or discomfort
  • Change in bowel habits, such as frequency or consistency or shape
  • Rectal bleeding or blood in stool
  • Bloating
  • Loss of appetite
  • Nausea/vomiting
  • Unintentional weight loss
  • Fatigue

These are common symptoms of gastrointestinal cancer, but there are more symptoms that relate specifically to each type.


How gastrointestinal cancer is diagnosed depends on what type of cancer is suspected. Lab tests, imaging tests, biopsies, and endoscopy are all methods of diagnosing many types of cancer.

Once cancer is confirmed, the stage of the cancer is then determined and a treatment plan is developed.


Treatment for gastrointestinal cancer depends on the type of cancer, stage, and other general health factors. Common methods of treating gastrointestinal cancer include surgery (most commonly used) chemotherapy and radiation therapy.


Each type of GI cancer has its own risk factors that we may be able to avoid, reducing the likelihood of developing cancer. Because some types of gastrointestinal have common risk factors, there are some general lifestyle changes we can make to reduce our risk.

Since we know that tobacco is linked to some types of gastrointestinal cancer, avoiding both is one of our best prevention defenses. The health benefits of not smoking are numerous and are not limited to preventing gastrointestinal cancer. By avoiding smoking, you drastically reduce your risk of many other types of cancer and other diseases.

Colon cancer screening is beneficial at detecting precancerous changes in the large intestine and rectum. For adults who are at average risk of colon and rectal cancer, it is recommended to begin screening at age 50. Adults who are classified at higher risk may begin screening earlier at the recommendation of their healthcare provider. Remember that even if you are not experiencing symptoms of colon or rectal cancer, you should always follow your healthcare provider's screening recommendations.

Lastly, eating a well-balanced diet is advantageous for many reasons. A diet rich in fruits and vegetables, low in animal fats, with a low sodium intake, may reduce your risk of some types of gastrointestinal cancer. Plus, eating a well-balanced diet can reduce obesity, a risk factor for many types of cancer.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Lisa Fayed
Lisa Fayed is a freelance medical writer, cancer educator and patient advocate.