Figure 2

Subgroup analysis for difficult colonoscopy in subjects of this study. Difficult colonoscopy was defined by the procedure with insertion time more than 10 min. The effects of distinctDCS (≤1 vs. >1) on cecal intubation completed more than 10 min were analyzed in subgroups of patients, which were stratified by gender, presence of constipation, prior history of abdominal or pelvic surgery, anxious status, patient types, indications of colonoscopy and quality of bowel preparation.