Gastrointestinal (GI) mucositis, which represents injury of the rest of the alimentary tract beyond oral mucositis, is becoming recognized increasingly as a toxicity associated with many standard-dose chemotherapy regimens. Although clinicians consider them "minor complaints", many patients (40-100%) treated with chemotherapy and/or exposed to ionizing radiation suffer from such a disease. After chemotherapy, GI mucositis is most prominent in the small intestine, but it also occurs in the esophagus, stomach, and large intestine. The GI symptoms related to mucositis mimic those from other GI disease (such as dyspepsia, reflux disease or abdominal pain and diarrhea). Alimentary tract mucositis increases morbility and mortality and contribute to rising health care cost.