Many patients have reported severe nausea and vomiting while undergoing chemotherapy treatments. However, many new antinausea drugs have made these symptoms much less common and severe than they were in the past. Different drugs work for different people, and sometimes it is necessary to take more than one medication to obtain relief.

Some drugs used in chemotherapy can cause sores in the mouth (stomatitis) and the throat (mucositis). Initially, the lining of the mouth may appear pale and dry. Later, the mouth, gums and throat may become sore, red and inflamed. The tongue may swell or become coated, leading to difficulty in swallowing (dysphagia), eating or talking. Patients who do not eat well after beginning treatments are most vulnerable to getting sores, which can bleed, ulcerate and become infected. Various medicines can treat mouth sores that may develop. The patient may be referred to a speech-language pathologist to help with the swallowing and communication problems. A dietitian also may be recommended to help with diet planning and nutritional support.

If chemotherapy damages normal cells in the intestine, diarrhea can result. Patients should consult a physician if they have diarrhea that lasts more than 24 hours or that is accompanied by pain and cramping. Intravenous fluids may be necessary to replace water and nutrients that have been lost to diarrhea. Medicines may be prescribed to treat the diarrhea. Over-the-counter medications should not be used unless approved by a physician.

Chemotherapy can also cause constipation, especially in patients who are less active or do not consume enough fluid or fiber. Other factors that may increase the risk of constipation include prolonged bed rest and depression. A patient’s cancer care team will work together to determine the best course of action to treat digestive problems related to chemotherapy and other cancer treatments.