texas oncology more breakthroughs. more victories
Some of our cancer centers may have important notifications found on the location page. View More Important Notifications x
Request an Appointment


While undergoing cancer treatment, some people experience diarrhea. Diarrhea is the passage of frequent and watery stools with or without pain. When the small intestine does not sufficiently absorb fluid or food, the excess is passed on to the large intestine rather than into the bloodstream. Diarrhea can cause dehydration and chemical imbalance, which can produce excessive thirst, weakness, and fatigue.

These problems can be brief or, if not managed effectively, may go on for many days and potentially result in other complications. Diarrhea can be caused by cancer itself, your treatment, other medications you are receiving, or stress.

Treating Diarrhea

To treat diarrhea, your doctor may prescribe antidiarrheal medication, intravenous fluids, or a change in diet. You can take the following steps as well:

  • Eat bland, low-fiber foods (such as white rice and mashed potatoes).
  • Eat foods that contain salt (sodium) and those high in potassium that don’t contribute to diarrhea, such as baked potatoes, halibut, asparagus tips, avocados, bananas, and citrus fruits.
  • Add nutmeg to your foods to decrease the motion in your gastrointestinal track.
  • Drink many clear fluids; avoid coffee, caffeinated tea, alcohol, and milk.
  • Avoid smoking.
  • Clean thoroughly after bowel movements. 

Skin Care During Bouts with Diarrhea

A potential problem related to diarrhea is skin sensitivity. Remember to take special care of the skin and membranes around your rectal area. After each bowel movement, clean yourself well with mild soap. Rinse gently and pat dry. Do not rub.

You may wish to use a sitz bath or sit in a tub of warm water to soothe your skin. Wipe with a premoistened wipe after each bowel movement and then apply a cream or ointment such as Vaseline®, Preparation H®, or Anusol® to protect skin from irritation and heal inflamed rectal tissue. Choose loose-fitting underwear to allow more air to reach the area. If you are still uncomfortable, speak to your care team about other possible solutions.


After food is broken down to waste products in your gastrointestinal (GI) tract, it moves through the intestines and is eliminated. Sometimes this process is slowed, causing irregular or infrequent bowel movements of hard, dry stools. Passing hard stools can be difficult or unsuccessful; you may experience discomfort, pain, or even develop hemorrhoids because of straining. This is constipation.

Like diarrhea, constipation can be caused by cancer itself, your treatment, other medications you are receiving, or stress. In addition, dehydration or bowel obstruction can contribute to constipation and can cause nausea, vomiting, hemorrhoids, and other problems.

Preventing Constipation

To prevent constipation, be sensitive to your body and any changes you note. You know your body best, and you know when you regularly have a bowel movement. Be sure to allow ample time, privacy, and respond as soon as you have the urge to have a bowel movement.

Even if you are doing the best you can to prevent constipation, other factors can interfere with your normal bowel routine. Fatigue slows the GI tract, allowing waste to become dry, hard, and difficult to pass. Fatigue can also rob you of the energy you need to have a bowel movement. If you are fatigued, it is important to take care of yourself by resting often.


Regular exercise is an important factor in stimulating bowel regularity. Walking is a simple yet effective way to achieve a regular exercise routine, but any type of daily exercise is beneficial.


The quality of your diet also affects bowel regularity. Make sure that your diet works for your system. Eating foods high in fiber keeps bowel movements regular and stools easy to pass. High fiber foods increase the volume of stools and pull water into the bowel, which helps soften the stools.

Avoid cheese products, refined grain, or other foods that may cause constipation. Instead, eat foods that are rich in fiber such as:

  • Whole-grain products
  • Bran
  • Nuts and seeds
  • Corn and popcorn
  • Fresh raw vegetables
  • Fruits with skins and peels
  • Coconut
  • Raisins, dates, and prunes
  • Prune juice


Drinking plenty of fluid throughout the day, especially fruit juice and water, will help prevent constipation. It is recommended that you drink at least six, eight-ounce glasses of water daily. In addition, sipping hot liquids right before attempting to have a bowel movement sometimes helps stimulate the bowels.

Treating Constipation

If you usually have a bowel movement every one to three days, but have gone past that time and are experiencing uncomfortable symptoms (such as bloating, abdominal cramping, or straining during bowel movements), be sure to call your care team. They will assess the situation and suggest ways to deal with the problem. They may encourage you to use stool softeners, laxatives, suppositories, and/or an enema.

However, sometimes conditions exist in which suppositories and/or enemas are not advisable, so always check with your care team before treating constipation yourself.

Stool Softeners

Stool softeners work naturally with your GI tract without irritating the intestines. The softeners absorb water and expand to increase bulk and moisture content of the stool, which in turn encourages “motility” (natural movement of stools through the intestines). Always check with your care team before using stool softeners.


If stool softeners alone are not effective, your care team may recommend laxatives to help you regain regularity. Laxatives work by stimulating the intestinal walls to move waste rapidly and forcefully through the digestive tract. Frequent use of laxatives can result in dependency, making it difficult to regain normal bowel habits. However, for those who are elderly or taking narcotic medications, use of laxatives may be required indefinitely. Always check with your care team before using laxatives.

Remember, when you experience side effects, it is important to contact Texas Oncology first before going to an emergency room or urgent care clinic.