This case series aims to evaluate the effectiveness and tolerability of Oral Sulfate Solution (OSS) in patients who had previously experienced poor colonoscopy preparation.

This study aims to evaluate the effectiveness of Oral Sodium Sulfate (OSS) in patients who have had poor colon preparation in the past. The study includes patients who had issues during their previous colonoscopy, such as needing extensive washing, inadequate preparation, a recommendation for shorter surveillance intervals, or adequate preparation for larger polyps but not smaller lesions.

Poor colon cleansing during a colonoscopy can lead to more prolonged procedures, lower polyp detection rates, and the need for repeat procedures with shorter surveillance intervals. OSS is a low-volume osmotic agent that causes diarrhea and colon cleansing by drawing water into the intestine. Health Canada and the FDA have approved it, and it is given in two 177ml bottles in a split dose. OSS is known for its good effect, ease of use, and tolerability, and it may be a better option than traditional cleansing agents.

All participants will receive OSS and instructions for use before their next surveillance colonoscopy. The study will use questionnaires and patient diaries to assess the effectiveness of OSS and patient compliance and tolerability.

Inclusion Criteria:

1. Patients Age 18 to 80 inclusive

2. Able to read and understand the English language

3. History of poor bowel prep defined as:

   • Required extensive washing, as noted in the narrative of the endoscopist report.
   • Inadequate preparation
   • Endoscopist recommended shorter interval surveillance due to poor prep
   • adequate for polyps >5mm but not smaller lesions

Exclusion Criteria:

1. Patients who have inflammatory bowel disease
2. Patients with ileus or bowel obstruction
3. Patients with history of colorectal resection
4. Patients receiving combined upper and lower endoscopies
5. Patients with ascites
6. Patients with previously documented severe renal impairment
7. Unable to provide consent
8. Pregnant or lactating female (females of child-bearing potential will undergo urine pregnancy testing)
9. Patients who have had a recent myocardial infarction(<6months)