A validated bowel-preparation tolerability questionnaire and assessment of three commonly used bowel-cleansing agents.

Bowel-cleansing studies are frequently underpowered, poorly designed, and with subjective assessments. Consensus on tolerability of the bowel-cleansing agents is thus lacking. This study developed and validated a bowel-preparation tolerability questionnaire and used it to assess the tolerability of three bowel-cleansing agents, sodium phosphate (NaP), polyethylene glycol (PEG), and sodium picosulphate (Pico), in a prospective randomized single-blinded trial of ambulatory patients. The bowel-preparation tolerability questionnaire was validated in 125 consecutive patients and then bowel-preparation agent tolerability was assessed in 634 patients in a prospective randomized single-blinded trial. The questionnaire's internal consistency was satisfactory with good to excellent "test-retest" reliability for aggregate tolerability and visual analogue scores. Validity assessment confirmed it as reliable and accurate. Of 634 patients, 97.8 % took >75 % of the allocated preparation and 98.9 % completed the questionnaire. Overall, Pico was better tolerated than PEG (p < 0.001) and NaP (p < 0.001). NaP was better tolerated than PEG (p < 0.001). Regardless of the bowel-preparation agent used, males tolerated them better than females (p = 0.009) as did patients having their procedure in the AM. Older patients, however, tolerated all preparations better than younger patients (p = 0.006). This study used the first validated bowel-preparation tolerability questionnaire and identified that age, sex, and procedure time all impacted tolerability. Overall, Pico was best tolerated, but PEG's tolerability in patients ≥60 years was equal to that of Pico and NaP, suggesting that PEG can be recommended for older patients to avoid the electrolyte disturbances associated with the osmotic preparations.