Diarrhea is defined as having loose stools 3 or more times per day and is named according to how long it lasts:
- Acute diarrhea lasts for less than 2 weeks, but often lasts only 1-2 days and goes away on its own.
- Persistent diarrhea lasts for 2 to 4 weeks.
- Chronic diarrhea is 3 or more loose stools per day for 4 or more weeks.
It can occur as a side effect of many treatments for lung cancer. Tell your healthcare team if your acute diarrhea does not clear up after 3 days. This can put you at risk of dehydration, which is when there is not enough water in your body. Your healthcare team can help prevent dehydration and provide treatment for diarrhea.
Signs and symptoms of diarrhea
The signs of diarrhea that you experience can vary based on what is causing it. Your healthcare team can decide which cause is most likely, and the best way to treat it.
Signs of diarrhea can include:
- Loose, watery stools
- Urgent need to move bowels
- Stomach cramps or pain
- Bloating and/or gas
- Nausea
- Mucus in the stool
Lung cancer treatments that can cause diarrhea
Lung cancer treatments, including chemotherapy, radiation therapy to the stomach area, immunotherapy, and targeted therapy, can cause diarrhea. This can happen for a few reasons.
- They can affect the way your body processes food and/or can irritate the lining of your digestive tract.
- Cancer treatments can affect how well your body is able to fight infections, putting you at higher risk for diarrhea.
If you are taking medicine to treat constipation (hard stool that is difficult to pass), diarrhea can sometimes occur as an unintended side effect.
Managing diarrhea
Your healthcare team can talk to you about ways to manage diarrhea. This may include changes to what you are eating and drinking.
Practical tips:
- Avoid milk and dairy products and spicy, greasy, or high-fiber foods.
- Avoid alcohol and caffeine.
- Drink lots of clear liquids, but not just water. Broth, fruit juice, rice water, coconut water, and Gatorade help replace lost salt and electrolytes.
- Eat BRAT foods: bananas, rice, applesauce, and toast.
- Wash your hands often to prevent infections.
When to contact your healthcare team
Diarrhea is a common side effect that is often easily treated. However, it can sometimes cause more serious issues, and there are times when urgent medical care may be needed. It’s always a good idea to tell a member of your healthcare team when you notice a side effect from treatment or a symptom that concerns you. Often, they can be prevented or eased with help from your healthcare team or through palliative care services.
Call your healthcare team right away if you have any of these more serious signs or symptoms:
- If diarrhea lasts for more than 3 days or more than 6 episodes of diarrhea occur per day for 2 or more days
- If diarrhea is black or includes blood or pus
- Fever of 100.5 degrees Fahrenheit or higher
- Difficulty controlling bowel movements
- Stomach cramps for more than a day, or any severe pain in the area
Frequently asked questions
Where can I find more resources and support?
Contact the GO2 HelpLine at 1-800-298-2436 or email support@go2.org to connect with caring and highly trained staff who listen, answer your questions, and provide support. We offer many free programs and educational resources to meet your needs.
Do all lung cancer treatments increase the risk of diarrhea?
Generally speaking, chemotherapy, immunotherapy, radiation therapy, and targeted therapies can all cause diarrhea. The risk is based on the specific medicine being used in treatment. Talk to your healthcare team about the risk of diarrhea with your treatment.
When should I be worried about diarrhea due to lung cancer treatment?
The main concern with diarrhea is dehydration, which is when there is not enough water in your body. If diarrhea continues for more than 3 days or you have bloody or black stool, fever, trouble controlling bowel movements, or pain, contact your healthcare team right away.