The purpose of this clinical study is to evaluate whether Bifidobacterium Triple Viable Capsules, alone or in combination with Gegen Qinlian Decoction, can effectively prevent and treat acute radiation enteritis in patients undergoing abdominal or pelvic radiotherapy.

The study aims to answer the following question: Can probiotics, with or without the addition of herbal medicine, reduce the incidence and severity of radiation-induced intestinal injury and improve the quality of life for patients during and after radiotherapy?

A total of 60 patients with malignant tumors receiving abdominal or pelvic radiotherapy will be recruited and randomly assigned to one of three groups: a control group (no intervention), a probiotics-only group (Bifidobacterium Triple Viable Capsules, three capsules twice daily), and a combination therapy group (probiotics with modified Gegen Qinlian Decoction tailored to individual symptoms).

The primary outcome will be the incidence and severity of acute radiation enteritis, assessed using the RTOG/EORTC grading criteria (0-IV levels). Daily observations will be recorded during radiotherapy, with follow-up lasting three months after the completion of treatment.

This study seeks to provide evidence for the use of probiotics and herbal medicine as effective strategies to mitigate the side effects of radiotherapy and improve patient outcomes.

Inclusion Criteria:1.Age:Participants aged 18 to 80 years.2.Diagnosis:

Patients diagnosed with malignant tumors confirmed by cytological or pathological examination.Patients scheduled for abdominal or pelvic radiotherapy based on treatment guidelines.3Cognitive and Communication Ability:Participants must have clear consciousness and normal cognitive abilities to communicate effectively.4.Consent:Participants must provide written informed consent and agree to participate in the study.

Family members must also provide consent if applicable.5.Willingness to Cooperate:Participants must be willing to comply with the study procedures and requirements.

Exclusion Criteria:1.History of Severe Intestinal Diseases:Patients with a history of severe intestinal diseases, including ischemic bowel disease, ulcerative colitis, Crohn's disease, or other chronic inflammatory bowel conditions.2.Recent Antibiotic Use:Patients who have received antibiotic treatment within the past 2 years.3.Severe Organ Dysfunction:Patients with severe liver or kidney dysfunction, as determined by clinical assessment or laboratory tests.4.Comorbidities and Other Major Diseases:

Patients with other serious illnesses that may interfere with the study protocol or compliance, including but not limited to cardiovascular, respiratory, or neurological diseases.5.Inability to Participate:Patients unable to cooperate with the study procedures due to physical or psychological reasons.Patients who are likely to withdraw midway through the study.6.Incomplete Medical Records or Refusal to Share Data:Patients who refuse to share their medical records or have incomplete medical documentation.