Colonoscopy preparation is often uncomfortable, leading some patients to question continuing the regimen. This intense cleansing phase is fundamental to the procedure’s success. Stopping the preparation early risks an incomplete or failed examination, negating the time and effort invested. The goal of the full regimen is to ensure the colon lining is completely visible for a thorough and accurate screening.
Visualizing Insufficient Preparation
Successful preparation is defined by the clarity of the fluid passed from the rectum. The output should be a clear, watery liquid, light yellow or transparent, similar to urine, indicating that only digestive fluids remain. Inadequate preparation involves cloudy, thick, or dark liquid, or visible solid particles. If the fluid is still brown or muddy, residual waste clings to the colon walls, meaning the colon is not truly empty.
The Immediate Outcome: Procedure Cancellation or Delay
Incomplete preparation often results in the cancellation or delay of the procedure. If visualization is poor after the endoscope is inserted, the physician cannot safely or effectively proceed. A colonoscopy performed on an unprepared bowel is considered a suboptimal study that wastes resources. Cancellation creates logistical and financial burdens, requiring the patient to reschedule and repeat the difficult preparation process. Furthermore, many centers charge a cancellation fee, often several hundred dollars, if the procedure is called off due to inadequate preparation.
Medical Risks of Poor Visualization
The most significant danger of poor visualization is the inability to detect precancerous lesions, the primary purpose of screening. Residual stool can hide small polyps or flatter, subtle lesions. If a polyp is obscured and missed, it may progress into cancer over time, negating the protective benefit of the screening. Inadequate preparation can result in an adenoma miss rate as high as 48% on repeat colonoscopy, creating a high risk of a “false negative” result. This undermines the screening’s purpose, leading to delayed diagnosis and increased risk of interval colorectal cancer.
Steps to Take If Prep Was Incomplete
If a patient suspects their preparation is inadequate, immediate communication with the medical team is necessary. Contact the prescribing physician or endoscopy center before the scheduled procedure, not the morning of the appointment. Honesty about the bowel movements allows the clinical staff to make an informed decision. Depending on the time remaining, the doctor may recommend a last-minute corrective measure, such as an additional laxative dose or an enema. If preparation is severely lacking, however, the procedure will likely need to be rescheduled for a proper clean-out.