Inclusion Criteria:

- Current diagnosis of cancer that supports the use of continuous definitive or
adjuvant external-beam RT to the abdomen or pelvis to a minimum dose of 4500 cGy.

- Scheduled to receive concurrent administration of fluoropyrimidine chemotherapy (5-FU
or capecitabine) during radiation therapy.

- Age ≥ 18 years.

- Life expectancy ≥ 6 months.

- Negative pregnancy test done ≤7 days prior to registration (for women of childbearing
potential only).

- The following laboratory values obtained ≤ 28 days prior to registration:

- Hemoglobin ≥ 10.0 g/dL

- WBC ≥ 3,500

- Absolute neutrophil count ≥ 1,500

- Platelets ≥ 100,000

- ECOG Performance Status (PS) of 0, 1, or 2.

- Willingness to abstain from ingestion of yogurt products and/or any product
containing probiotics during study drug treatment.

- Ability to complete questionnaire(s) alone or with assistance.

- Ability to understand and willingness to sign informed consent.

Exclusion Criteria:

- Previous significant bowel resection.

- Known allergy to a probiotic preparation.

- Any history of inflammatory bowel disease.

- Grade 3 or 4 diarrhea, rectal bleeding, abdominal cramping, or incontinence of stool
≤7 days prior to registration.

- Any medical condition that may interfere with ability to receive protocol treatment.

- Prior abdominal or pelvic RT.

7-Use of probiotics ≤ 2 weeks prior to registration.

- Use of antibiotics ≤ 3 days prior to registration.

- Planned continuous antibiotic treatment during RT.

- History of gastrointestinal or genitourinary obstruction or porphyria.

History of irritable bowel syndrome (IBS).

Inclusion of Women and Minorities

-Both men and women and members of all races and ethnic groups are eligible for this
trial.