Ropidoxuridine in Treating Patients With Advanced Gastrointestinal Cancer Undergoing Radiation Therapy

Inclusion Criteria: * Patients must have histologically or cytologically confirmed advanced, incurable cancers of the esophagus, liver, stomach, small bowel, pancreas, bile duct, colon or rectum and be eligible to receive chest, abdominal and/or pelvic radiation therapy (RT) for palliation; documentation of this is required in physician note; concomitant systemic therapy is not allowed during administration of palliative RT; palliative RT can be considered for advanced primary tumors or metastatic disease as above * Patients must not have received systemic chemotherapy for at least 4 weeks, and must not have received prior radiation therapy to the tumor site being irradiated on this study * Eastern Cooperative Oncology Group (ECOG) performance status =\< 2 (Karnofsky \>= 60%) * Life expectancy of greater than 12 weeks * Leukocytes \>= 3,000/mcL * Absolute neutrophil count \>= 1,500/mcL * Platelets \>= 100,000/mcL * Total bilirubin within normal institutional limits * Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase \[SGOT\])/alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase \[SGPT\]) =\< 2.5 x institutional upper limit of normal * Creatinine within normal institutional limits OR creatinine clearance \>= 60 mL/min/1.73 m\^2 for patients with creatinine levels above institutional normal * Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior …