About 20-40% of all colonoscopies have inadequate bowel prep. How do we prevent this from happening again to the same patient? There is very little research to guide us. Take these steps to prevent a 2nd poor prep.

  • Before performing colonoscopy in a patient, ask whether the patient followed the bowel preparation instructions especially instructions on home medications and diet. If the answer is no, ask for the reason. Also, ask whether the patient consumed the entire bowel prep agent. If the answer is no. Ask for the reason. Large volume? Adverse event? Poor taste?
  • Perform the colonoscopy using water irrigation and suctioning to improve the bowel prep score as much as possible. The quality of bowel prep should be judged after efforts to clear residual debris have been completed.
  • If the quality of the prep is deemed inadequate, a repeat colonoscopy should be recommended within 6 months.
  • Bowel instruction and bowel preparation agent for a repeat colonoscopy due to inadequate bowel prep should be based on the following: Did the patient follow the bowel preparation instructions especially instructions on home medications and diet? Did the patient consume the entire bowel prep agent? Does the patient have risk factors for inadequate bowel prep? These risk factors can be classified into medical and non-medical factors. Medical factors include prior inadequate bowel prep, chronic constipation, use of constipating medications like psychotropics, opioid narcotics, diabetes mellitus, obesity, prior resection of the colon, stroke, dementia, cirrhosis, parkinson’s disease, ≥8 active prescription medications, prior abdominal surgeries like appendectomy and hysterectomy. Non-medical factors include age > 60 years, male gender, single or widowed status, English as a 2nd language, lower household income, low patient activation, low health literacy, longer wait time, Medicaid insurance, in-patient status, afternoon colonoscopies, lower educational level, and ≤ 12th grade education.
  • If the patient did not follow the bowel preparation instruction. Provide clear, understandable instructions. Provide instructions in the patient’s language. Provide instructions in multiple formats (verbal, brochures, and video). Open communication channels for further questions and answers. Involve a family member or friend. Perform telephone re-education a day before colonoscopy. Use instruction reminders (stickers, alarm clocks, phone apps).
  • If the patient did not complete bowel prep agent due to side effect, provide remedies and advice regarding adverse events and how to manage them.
  • If the patient did not complete the prep due to the bad taste of the prep agent, use sulfate-free alternatives. Consider adding flavors. Refrigerate the solution. Use a straw. Suck on menthol candy while consuming the bowel prep agent.
  • If the patient did not complete bowel prep agent due to the large volume nature of bowel prep agent, consider using a low-volume agent with a bowel prep adjuncts such as magnesium citrate or bisacodyl.
  • If the patient followed the bowel prep instructions and consumed all bowel prep agent, consider the following strategy: low fiber diet x 72hrs, liquid diet x 24hrs, bisacodyl 10mg evening (or 1 bottle of magnesium citrate) the night before colonoscopy and Split-dose large volume PEG-based formulation OR clear liquid diet x 2 days prior to colonoscopy ± bisacodyl 10mg evening (or 1 bottle of magnesium citrate) the night before colonoscopy and Split-dose large volume PEG-based formulation OR clear liquid diet x 2 days PLUS 6-8L of PEG-based formulation in split-dose over 2 days.
  • The good news is that if patients truly follow all bowel prep instructions and consume all bowel prep agents, the chances of having inadequate bowel prep are low.
  • For more ideas on bowel prep, refer your patients to www.bowelprepguide.com.