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Cancer Health Center

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Gastrointestinal Complications (PDQ®): Supportive care - Health Professional Information [NCI] - Diarrhea

The reported prevalence and severity of diarrhea vary greatly. Some chemotherapeutic regimens are associated with diarrhea rates as high as 50% to 80%, particularly those containing fluoropyrimidines or irinotecan.[1,2] Diarrhea is also commonly observed in patients diagnosed with carcinoid tumors, receiving radiation therapy to abdominal/pelvic fields, or undergoing bone marrow transplantation or surgical intervention of the gastrointestinal tract.[3] In a large heterogeneous sample of cancer patients in various stages of treatment, the prevalence of moderate-to-severe diarrhea was 14%.[4] Diarrhea occurs in approximately 7% to 10% of cancer patients upon admission to hospice.[5] Among children with cancer during the last month of life, 19% experienced diarrhea.[6]

The consequences of diarrhea can be significant and life-threatening. According to the National Cancer Institute's (NCI's) Common Terminology Criteria for Adverse Events, more than half of patients receiving chemotherapy for colorectal cancer experienced diarrhea of grade 3 or grade 4, requiring treatment changes or the reduction, delay, or discontinuation of therapy (see Table 1).[7,8] A review of several clinical trials of irinotecan plus high-dose fluorouracil and leucovorin in colorectal cancer revealed early death rates of 2.2% to 4.8%, primarily due to gastrointestinal toxicity.[9] With the advent of more aggressive anticancer therapies, the potential physical and psychosocial consequences of diarrhea and its indirect effect on cancer treatment outcome are likely to expand.[10]

Table 1. National Cancer Institute's Common Terminology Criteria for Adverse Events: Diarrheaa,b

ADL = activities of daily living.
a Adapted from National Cancer Institute.[8]
b Definition: A disorder characterized by frequent and watery bowel movements.
c Self-care ADL refers to bathing, dressing and undressing, feeding self, using the toilet, taking medications, and not bedridden.
1Increase of <4 stools/day over baseline; mild increase in ostomy output compared with baseline
2Increase of 4-6 stools/day over baseline; moderate increase in ostomy output compared with baseline
3Increase of ≥7 stools/day over baseline; incontinence; hospitalization indicated; severe increase in ostomy output compared with baseline; limiting self-care ADLc
4Life-threatening consequences; urgent intervention indicated

Etiology of Diarrhea

In patients being treated for cancer, diarrhea is most commonly induced by therapy.[11] Conventional methods of diarrhea-causing treatment include the following:

  • Surgery.
  • Chemotherapy.
  • Radiation therapy.
  • Bone marrow transplantation.
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