Small Intestine Cancer: Signs and Symptoms

Small intestine cancer is a rare cancer that develops in the tissues of the small intestine, a 20-foot-long organ that connects the stomach to the large intestine (colon). Its job is to break down food and absorb nutrients.

When cancer develops in your small intestine, it can cause symptoms like abdominal pain, bloating, unexplained weight loss, and bloody poop.

The American Cancer Society estimates that there will be 12,440 new cases of small intestine cancer in the United States in 2024, making this cancer more uncommon than other cancers. Understanding the warning signs is still essential so you can know when to seek healthcare for your symptoms.

Early symptoms of small intestine cancer may seem vague and can easily be mistaken for other conditions. Common warning signs include:

• Abdominal pain or cramping
• Nausea and vomiting 
• Bloating
• Loss of appetite

The abdominal pain caused by small intestine cancer may feel dull, achy, or crampy. It often comes and goes and can worsen while eating, which may happen because food can no longer pass through the small intestine as easily.

As small intestine cancer grows and spreads, it can cause more intense symptoms. When the tumor in the small intestine grows, it blocks food from passing through to the colon, usually causing more abdominal pain.

If the tumor completely blocks the small intestine, you may experience more progressive symptoms, such as:

• Muscle weakness
• Fatigue 
• Unintended weight loss
• Black or dark-colored stools
• Jaundice (yellowing of the skin and eyes)
• A lump in the abdomen 
• Distended (swollen) abdomen

Later-stage small intestine cancer can cause several serious symptoms. As the cancerous tumor grows, it may cause damage to the surrounding tissues, leading to symptoms like:

• Internal bleeding in the small intestine
• Anemia, which can lead to weakness, fatigue, and pale skin
• Perforation (hole) in the wall of the small intestine, which can cause sudden abdominal pain and nausea
• Liver-related symptoms, which can occur as cancer spreads to the liver and cause lesions, abdominal pain, diarrhea, shortness of breath, and bloating

Small intestine cancer is rare in adults and extremely rare in children. If a child develops this cancer, the most common symptoms are abdominal pain and vomiting. It’s important to note that these symptoms are usually related to a noncancerous cause like an illness or viral infection. 

It can be hard to know when to call your healthcare provider about possible small intestine cancer symptoms. Many of the symptoms of early-stage small intestine cancer could also be caused by a less serious condition like an infectious illness. 

You may consider contacting your healthcare provider if you develop abdominal pain that worsens after eating, a loss of appetite, or nausea and vomiting that doesn’t improve.

Because small intestine cancer is rare, your symptoms may often be due to another underlying condition or illness. Nevertheless, seeing your provider about any concerning symptoms is still important and can help you get the treatment you need to feel better.

Small intestine cancer develops in the tissues of the small intestine, usually causing early symptoms such as abdominal pain, bloating, and nausea. The cancer cells can spread and cause more advanced symptoms without an early diagnosis and treatment.

These symptoms may include fatigue, unintended weight loss, anemia, and jaundice. While small intestine cancer is rare, seeing your healthcare provider for proper testing and treatment, if necessary, is still important.