Efficacy and Safety of Adjunctive Use of Rifaximin In Preventing Radiotherapy-induced Diarrhea in Cancer Patients

Inclusion Criteria: * Individuals who are 18 years of age or older and have been diagnosed with non metastatic pelvic cancers. * Patients who are undergoing curative intent radiotherapy with or without chemotherapy treatment. Exclusion Criteria: * Patients who have a record of intestinal resection in their medical history. * Patients with a medical background of irritable bowel syndrome. * Patients with a history of inflammatory bowel disease. * Patients who regularly take anti-diarrheal medications before commencing radiotherapy. * Patients experiencing diarrhea at the outset of the study. * Patients with compromised immune systems, such as those who are HIV positive or using immunosuppressive medications. * Pregnant or lactating woman. * Patients allergic to rifamycin.