History of acute or chronic regional enteritis or inflammatory bowel disease

Stool incontinence

Uncontrollable diarrhea

Abdominal-perineal resection or other surgery leaving patient without a functioning rectum

Patients using colostomy or ileostomy

Liver function tests \> 3x upper limit of normal, or bilirubin test result \> 1.5 the upper limit of normal

Calculated creatinine clearance \<60 mL/minute

Planned hyperfractionated or split course radiation

Planned brachytherapy prior to completion of all external beam radiation therapy

Prior pelvic RT

An on-going infection

ECOG score \>/= 3

Leukopenia \<2,000 WBC/mm3 or Hg \<10.5 g/dL

Participation in an investigational drug trial within the previous 30 days

Patients with a medical condition that would interfere with study compliance

Known hypersensitivity to 5-FU or capecitabine

Anticipated inability to tolerate oral administration of SGX201

Pregnant or breastfeeding

A Dose Ranging Study of Delayed Release Beclomethasone for Prevention of Acute Enteritis in Patients With Rectal Cancer