BACKGROUND: Interstitial cystitis (IC) is a chronic condition with complex symptoms, including pelvic pain and urinary frequency. Current treatments often involve a combination of therapies, but their effectiveness remains a topic of ongoing investigation. This study aimed to evaluate the clinical efficacy of a treatment regimen combining intravesical instillation of heparin and alkalized lidocaine, hydrodistention, and transurethral fulguration, using pelvic ultrasound monitoring and symptom scales to assess patient outcomes. METHODS: From June 2016 to June 2023, patients who were diagnosed as interstitial cystitis in urology department of the xuzhou central hospital were selected. All patients received intravesical instillation regimen of 2% lidocaine 10 ml + 5% sodium bicarbonate 5 ml + heparin 25000 IU for 6 months, and they were randomly divided into two groups according to the simple randomization (coin toss): hydrodistention and transurethral fulguration (HD/TF) group and non-HD/TF group. The 24-h urination frequency, nocturia frequency, pelvic ultrasound measurement results (bladder volume at maximum filling state, bladder wall thickness after urination, residual urine volume), O'Leary-Sant interstitial cystitis symptom index (ICSI), O'Leary-Sant interstitial cystitis problem index (ICPI), pelvic pain and urgency/frequency (PUF), pain visual analogue score (VAS), self-rating anxiety scale (SAS) were recorded before treatment and 3 and 6 months after treatment. RESULTS: A total of 68 patients were included in this study, including 13 males (19.12%) and 55 females (80.88%), with an average age of 59.07 ± 8.15 years. According to the simple randomization, 68 patients were randomly divided into HD/TF group (n = 30) and non-HD/TF group (n = 38). After the 3rd and 6 th months of treatment, the 24-h urination frequency and nocturia frequency in both groups decreased significantly (P < 0.05), and the 24-h urination frequency and nocturia frequency after the 3rd and 6 th months of treatment in HD/TF group decreased significantly compared with that in non-HD/TF group (P < 0.05). After the 3rd and 6 th months of treatment, the bladder volume at maximum filling state in the two groups increased and the residual urine volume decreased (P < 0.05). In addition, the bladder volume at maximum filling state of the HD/TF group increased significantly compared to the non-HD/TF group after 3rd and 6 th months of treatment (P < 0.05), while the bladder wall thickness after urination decreased compared to the non-HD/TF group after 3rd months of treatment (P < 0.05). There was no significant difference in residual urine volume between HD/TF group and non-HD/TF group before and after treatment (P > 0.05). The postoperative scores at 3rd and 6 th months of ICPI, ICSI, PUF, SAS and VAS in both groups were significantly lower than those before treatment (P < 0.05), and The postoperative scores at 3rd and 6 th months of ICPI, ICSI, PUF, SAS and VAS in HD/TF group were significantly lower than those in non-HD/TF group (P < 0.05). CONCLUSIONS: Intravesical instillation of heparin/alkalized lidocaine combined with hydrodistention and transurethral fulguration is an effective treatment for interstitial cystitis, which can significantly reduce patient pain and improve patient prognosis. Moreover, the use of pelvic ultrasound to monitor indicators such as bladder volume at maximum filling state and residual urine volume, combined with ICSI, ICPI, PUF, VAS, and SAS scores, has high application value for evaluating the efficacy of intravesical instillation regimen combined with hydrodistention and transurethral fulguration in the treatment of interstitial cystitis.