Rifaximin and Placebo in the Treatment of Bowel Dysfunction After Anterior Resection for Rectal Cancer

Phase 3

Completed

Brief Summary: The most common long-term problems after rectal surgery are bowel problems. These problems can include needing to pass bowel movements a lot, loose or mushy stools, inability to fully clear your bowels, and/or poor control of gas and stool. The investigators believe that a major cause of these problems is too much bacteria in the bowel and treatment with antibiotic tablets will hopefully help improve these bowel problems. In order to test this idea, the Colorectal Surgery Service of Memorial Sloan Kettering Cancer Center is sponsoring a clinical trial. This trial will compare the antibiotic rifaximin and a placebo (a harmless tablet that has no effect) in the treatment of these bowel problems. Following this we will attempt to see if another antibiotic metronidazole also helps to treat these bowel problems. Both Metronidazole and rifaximin are well established drugs that have minimal side effects.

Recruitment & Eligibility

Inclusion Criteria

Patients with a history of rectal cancer treated with an anterior resection preformed at MSKCC (tumor at or below 12cm from anal verge) with restoration of bowel continuity ≥1 and ≤ 5 years. (Patients may also have had procedures to construct neo-rectums including j-pouch, coloplasty, and end to side anastomosis).
Patients ≥ 21 years of age.
Presence of anterior resection symptoms by patients own assessment. These symptoms may include any of the following: incomplete evacuation, clustering of bowel motions, frequency of bowel motions, unformed stool, excessive flatus, or incontinence of flatus and/or feces.

Exclusion Criteria

Arm && Interventions

Group	Intervention	Description
Pts receiving placebo	Placebo	This group will receive a placebo bid for 4 weeks. At 1 - 24 months after completion of the phase III portion of the trial, patients will be contacted by phone and given the option of receiving metronidazole in a followup, single arm study in which all patients receive the antibiotic. Patients who wish to participate will be mailed a drug prescription for a 3 week course of metronidazole 500mgs tid as well as the BFI forms and stool diary. Pretreatment and post treatment BFI scores will be collected and analyzed for change in bowel function as was done in the initial Phase III study.
Pts receiving Rifaximin	Rifaximin	This group will receive rifaximin 400mg bid for 4 weeks. At 1 - 24 months after completion of the phase III portion of the trial, patients will be contacted by phone and given the option of receiving metronidazole in a followup, single arm study in which all patients receive the antibiotic. Patients who wish to participate will be mailed a drug prescription for a 3 week course of metronidazole 500mgs tid as well as the BFI forms and stool diary. Pretreatment and post treatment BFI scores will be collected and analyzed for change in bowel function as was done in the initial Phase III study.

Primary Outcome Measures

Name	Time	Method
Number of Participants Who Completed MSKCC Bowel Function Instrument (BFI Score) in Patients Following Anterior Resection (AR) or Sphincter Preserving Surgery (SPS) for Rectal Cancer.	1 year

Secondary Outcome Measures

Name	Time	Method
To Identify Dynamic Changes in Bowel Function During and After Antibiotic Treatment Using a Bowel Function Log.	1 year
To Determine if Reduction in Intestinal Bacterial Quantity Correlates With Improvement in Bowel Symptoms (BFI Score).	1 year
Efficacy of Metronidazole	1 year	in the treatment of bowel dysfunction as measured by the MSKCC BFI in patients following AR or SPS for rectal cancer for patients who have no improvement following treatment with rifaximin or placebo.
To Explore the Bacterial Composition of Stool Before and After Antibiotic Treatment.	1 year

Locations (3): Memorial Sloan Kettering Cancer Center Commack
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Commack, New York, United States
Memorial Sloan Kettering Cancer Center
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New York, New York, United States
Memorial Sloan Kettering Cancer Center at Basking Ridge
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Basking Ridge, New Jersey, United States