Multiple studies have examined the predictors of inadequate bowel preparation. These predictors or risk factors can be classified as medical factors and non-medical factors; patient-related and non-patient related; modifiable and non-modifiable. The table shows the predictors classified as medical factors and non-medical factors.

Predictors of Inadequate Bowel Preparation

Medical FactorsNon-Medical Conditions
Prior inadequate bowel prepAge > 60 years
Chronic constipationMale gender
Use of constipating medications like psychotropics, opioid narcoticsSingle or widowed status
Diabetes MellitusEnglish as a 2nd language
ObesityLower household income
Prior resection of the colonLow patient activation prior to colonoscopy
Stroke Low health literacy
DementiaLonger wait times for colonoscopy
CirrhosisMedicaid insurance
Parkinson diseaseIn-patient status
≥8 active prescription medicationsAfternoon colonoscopies
Prior abdominal surgeries like appendectomy, hysterectomyLower educational level, ≤ 12th grade education