Nutrition & Cancer Dealing with Changes in Eating & Digestion 

Summary: Patients experience many changes to their digestion and gastrointestinal tracts while going through their cancer treatments. Eating can become difficult and tiresome but must be done to ensure the body has the nutrition needed to fight this battle. Read on about nausea, vomiting, constipation and diarrhea and how you can work towards easing your symptoms.

Many cancer patients will face difficulties with eating and digestion related side effects while going through their treatment. While every patient reacts differently to their treatment, these side effects will not affect everyone in the same ways. Some of the treatment related changes with eating and digestion can be very embarrassing to deal with or discuss. Remember that many patients have dealt with and gone through the very same issues, and many can empathize with your feelings.

If you do experience challenges, know that you may need to try multiple methods for relief, before you truly find any. There are many ways to successfully treat and deal with these symptoms and issues at home, once you are aware of how to best handle your issues.

Nausea and Vomiting

The most common symptoms of cancer treatment are nausea and vomiting and are most often caused by chemotherapy or radiation. These symptoms can also occur due to other medical issues or from an obstruction. Chemotherapy can cause different types of nausea. They are:

  • anticipatory occurs before receiving chemo
  • acute occurs within the first twenty-four hours after chemo
  • delayed occurs one to four days after chemo

Frequent vomiting can make it difficult to get the hydration and nutrition that you need. Be cautious of dehydration, and allowing yourself to become dehydrated, which will only make matters worse. Tell your doctor if you are suffering from this. They will be able to assist you by prescribing some form of anti-nausea medication.

When you are feeling nauseated and sick to your stomach, do not force yourself to eat or drink. Taking small sips of water or clear liquids may help to calm your stomach and help to level out your electrolytes. If you continue to vomit, wait thirty-minutes between each instance before attempting anything by mouth. These suggestions may help you deal with the persistent nausea and vomiting before, during and after your treatment:

  • Sip on fluids before and during your cancer treatment. These extra fluids will help your body rid the chemotherapy biproducts and help you to stay hydrated.
  • Eat a light meal before your chemotherapy treatment. Choose foods that are easy to digest like soups, cottage cheese or crackers. During the treatment, sip on clear liquids like fruit juice, sports drinks, or ginger ale.
  • If you are in bed, lie on your side with your head elevated. If you are still vomiting, side laying may not feel right. Lying on your left side may be easier than your right and help to hold your stomach contents in place.
  • If you cannot swallow or are unable to keep fluids down, contact your doctor to find out if they can prescribe you an antiemetic medication in a suppository form, or the new dissolvable tablets.
  • If liquids are hard to keep down, try frozen liquids: ice cubes, fruit juice popsicles, or frozen juice chips- which can all be slowly sucked on, melted, and gently enter your gastrointestinal tract.

Do not wait to call the doctor if you experience any of the following things:

  • Weakness, lightheadedness, or dizziness
  • Inability to take needed medications
  • Inability to eat food for two or more days
  • Inability to have more than four cups or liquids or ice chips in a twenty-four-hour period
  • Blood or material that looks like coffee grounds in vomit
  • Vomiting more than three times an hour for three or more hours
  • Inhaled or swallowed vomit

If you are suffering from nausea and vomiting, focus on liquids and keeping your body hydrated. Begin by taking sips of room temperature fluids, very slowly. Once you are able to tolerate the small sips, take a small step up and consider trying these things:

  • Snack on dry foods like crackers, pretzels, toast, or dry cereals whenever you can. This helps to soak up any stomach acid that could be contributing to the nausea and helps to regulate your blood sugar.
  • Slowly add things like room temperature Jello, Popsicles, fruit ices, or even sorbet.
  • After you can handle things like those, begin to eat small, frequent snacks.
  • Many patients report that eating room temperature or cold foods are easier than hot.
  • Avoid eating or resting in rooms that are too warm, which will not allow your body to regulate properly.
  • Ginger supplements have shown to have some effect in reducing treatment-related nausea. Ask your dietician or doctor if these supplements may be beneficial for you.
  • Rinse your mouth before and after meals, but do not use mouthwash with alcohol as an ingredient. You can also use a simple mixture of one teaspoon baking soda and one teaspoon of salt in one quart of room temperature water. Rinse, then spit.
  • Avoid laying flat after eating or drinking for at least one hour.
  • Sucking on hard candies like sugar free lemon drops, peppermints, or tart candies help to relieve nausea symptoms.
  • If you have painful burps, or problems with continued burping, consult with your doctor about an antacid regimen.

Now that my treatment has begun, I cannot have a bowel movement to save my life. Is this normal?

Yes, constipation is very common before, during and after your cancer treatment. This happens when the bowels slow down and pass stool less frequently. There are many reasons this can happen, from dehydration to a normal side effect of the chemo medication. Pain medications are also known bowel-stoppers. If you have any of the following symptoms, your doctor can help you to determine how to best treat your constipation.

  • Vomiting and nausea
  • Cramps
  • Stomach pain
  • No bowel movement for three days
  • Gas and bloating
  • Any pain of localized discomfort

If you are suffering from constipation, keep a record of all of your bowel movements, and use your doctor’s fecal scaling numbers to identify the consistency, color and any other details your doctor needs to know. You can also consider stimulating your bowels with one of these methods:

  • Drink plenty of healthy fluids to help keep your digestive system moving
  • Try to establish a regular routine for your bowel movements, including the time of day
  • Avoid straining or using extreme force to push out the fecal matter
  • Try to eat and snack at the same times each day
  • Lessen the amount of air your swallow when you eat by talking less during meals and drinking without using a straw.
  • Exercise as much as possible. If you are stuck in bed, try bed exercises and focused abdominal bed routines.
  • Use stool softeners or laxatives if your doctor tells you this is best for you
  • Try a fiber-containing product like Benefiber or Citrucel.
  • Meet with a dietician to have assistance creating a nutritional plan that includes natural foods to help start your bowels.

After each of my treatments, I have diarrhea for days. What can I do to cope, and when should I call my doctor?

Diarrhea is another major side effect experienced by many cancer patients going through treatment. Diarrhea is the passage of loose and watery stool three or more times per day. Diarrhea can happen with or without pain and cramping in the abdomen. There are many things that can cause diarrhea, from bacteria, to illness, to medications, and stress. Diarrhea caused from treatment may last several weeks after treatment ends. Talk to your doctor immediately if you are experiencing diarrhea and weight loss, dehydration or decreased energy.

There are ways that you can cope with diarrhea and attempt to continue life while being ready at the drop of a dime to handle your business. During your bouts of diarrhea, drink more liquids to keep your body hydrated. When it begins to improve, eat only low fiber, easy to digest foods that are bland. This might be a banana, rice, mashed potatoes or applesauce. Monitor the amount and frequency of each bowel movement, and try these things:

  • Follow a clear liquid diet which consists of water, weak tea, apple juice, peach nectar, clear broth, popsicles or Jell-O.
  • Eat frequent, small meals.
  • Eat stool thickening foods like bananas, canned peaches or pears, oatmeal, white rice or pasta.
  • Eat foods high in potassium because this mineral helps muscles to function correctly and is depleted quickly during diarrhea.
  • Drink and eat foods high in sodium like soups, broths, or sports drinks.
  • Tell your doctor if your diarrhea lasts longer than two days.
  • Drink at least one cup of liquids after each bowel movement with diarrhea.
  • Avoid caffeine and alcohol.

When experiencing diarrhea, you should call the doctor if any of these symptoms present:

  • Fever
  • Inability to drink any liquids for two days
  • Inability to urinate for twelve hours or more
  • Abdominal cramps or pains lasting two days or more
  • Weight loss of five pounds or more
  • Blood in and or around the anal area
  • Six or more loose bowel movements per day, with no improvement
  • Suddenly bloated abdomen
  • Constipation for several days followed by sudden bursts of diarrhea or oozing fecal matter
  • Undigested food particle in stool

If you are experiencing any gastrointestinal discomfort or trouble with eating and getting nutrition during your treatment, contact your medical care team to schedule testing and appointments to get you back on track. Having a healthy diet is a vital aspect of your treatment and helping your body ready for the load of chemotherapy and radiation.

Resources Used:

Reclaiming Intimacy



The American Cancer Society’s Complete Guide to Nutrition, Barbara Grant, ISBN0944235786

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