Objective: To investigate functional outcomes and condition-specific quality-of-life (CSQoL) after intersphincteric resection (ISR) in patients with low rectal cancer using traditional and exploratory questionnaires. Methods: A prospective observational study was conducted in the Characteristic Medical Center of the People's Liberation Army Rocket Force. Patients with low rectal cancer who underwent ISR with ileostomy reversal from May 2020 to April 2023 were enrolled. An electronic self-assessment survey was sent to enrolled patients at 3 to 6, 12, and 24 to 36 months after reversal, and differences in functional and CSQoL results between the 3 groups were analyzed with generalized estimation equations. Functional outcomes were determined by the Wexner incontinence score (WIS) and the low anterior resection syndrome (LARS) score. In line with the five frequency responses ranging from never (score 0) to always (score 4) defined by the WIS, an exploratory survey was used to measure the severity of 16 LARS-specific variables confirmed by the latest international Delphi consensus. Furthermore, CSQoL was evaluated using the fecal incontinence quality-of-life scale (FIQL) and the visual analog scale (VAS). Results: A total of 90 patients were enrolled in the study. There were 64 males and 26 females, aged (58.6±10.4) years (range: 28 to 79 years). The median distance from the distal tumor margin to the anal verge(M(IQR)) was 3.0 (1.5) cm (range: 1.0 to 5.0 cm). There were 55 patients who completed the questionnaires at 3 to 6 months, 59 patients at 12 months, and 40 patients at 24 to 36 months of follow-up, respectively. The summary score of FIQL and VAS improved significantly after reversal (2.33±0.69 vs. 2.40±0.66 vs. 2.79±0.76, χ2=11.703,P=0.003; 5.31±1.65 vs. 5.61±1.90 vs. 6.58±1.92, χ2=12.781,P=0.002), but the differences in the WIS and LARS score did not reach statistical significance (both P>0.05). The survey responses for the LARS-specific variables indicated that "emptying difficulties" and "dissatisfaction with the bowels" were the most frequent symptom and consequence after ISR, respectively. The exploratory severity score for LARS improved significantly among the 3 time periods(34 (14) vs. 31 (13) vs. 23 (17), χ2=13.952,P=0.001). Furthermore, the FIQL summary score was strongly correlated with the LARS severity score (rs=-0.72, P<0.01). Conclusions: Although a high prevalence of LARS may persist for years, patients reported an improvement in CSQoL and functional outcomes after ISR. The highest priorities recommended by the international consensus might provide better assessments the severity of LARS.