Objective To investigate the validity of estimating American Spinal Injury Association Impairment Scale (AIS) grade with a bowel-routine based self-administered questionnaire for assessment of sacral sparing after spinal cord injury (SCI).Methods The 5-item SCI sacral sparing self-report questionnaire was administrated to SCI inpatients from August 2014 to July 2016, followed by an standardized digital rectal examination. Question 1 (perceiving the tissue), Question 2 (identifying the water temperature as warm or cold), Question 3 (perceiving the inserted finger), and Question 4 (perceiving the inserted enema tube) tested the sensory sacral sparing, and Question 5 (holding the enema for more than 1 min) evaluated the voluntary anal sphincter contraction. Based on the answers from each participant, the sensory and motor sacral sparing was implied, and an estimated AIS grade (AIS A, AIS B, or AIS C/D) was recorded. Agreement of the estimated AIS grade and the actual AIS grade according to the physical examination was analyzed. Sensitivity, specificity, and Youden’s index of the questionnaire for estimating completeness of injury were calculated.ResultsA total of 102 SCI patients were enrolled. The general agreement of estimated and actual AIS grades was good (κ=0.681, P<0.001). For the estimation of a complete injury, both the sensitivity (87.10%) and the specificity (100.00%) of this questionnaire were high, with a Youden’s index of 0.87. For the estimation of a motor complete injury, the sensitivity increased (92.00%) while the specificity decreased slightly (75.00%), with a Youden’s index of 0.67.ConclusionsThe validity of this self-report questionnaire for estimation of AIS grade is good. In some situations, it could be considered as an alternative tool for the estimation of sacral sparing as well as the AIS grades within SCI individuals, especially when repeated anorectal examinations are not feasible.