The time spent on the toilet during colonoscopy prep typically ranges from about 12 to 16 hours of frequent bowel movements, mostly diarrhea-like, as the colon needs to be thoroughly emptied. The laxatives usually start working within 1 to 3 hours after the first dose, and you may be on and off the toilet every 10 to 15 minutes during the peak of the prep. Most people finish the process before their colonoscopy appointment, often the night before if scheduled in the morning or with a split dose prep. The goal is to have clear or light yellow, watery stool to confirm the prep is complete. Actual toilet time per visit is usually short, often just a few minutes at a time, but can add up over several hours of repeated visits.

What to Expect

• Laxatives begin working within 1-3 hours.
• Frequent bowel movements, often every 10-15 minutes, for several hours.
• Stool changes from loose to clear or light yellow watery consistency.
• Total time "active" with cleansing bowel movements is around 12-16 hours but involves mostly short visits to the toilet spaced out over that time.
• Most people finish prep the night before or early morning on the day of the procedure if doing a split dose.

Tips for Comfort

• Stay close to the toilet.
• Use wet wipes and petroleum jelly to prevent irritation.
• Prepare for some fatigue and rest once clear.

This means, while you won't be on the toilet continuously for hours non-stop, you should expect many visits over many hours, adding up to a significant cumulative amount of toilet time during the colonoscopy prep.