Gastroenterol Res

Gastroenterology Research, ISSN 1918-2805 print, 1918-2813 online, Open Access

Article copyright, the authors; Journal compilation copyright, Gastroenterol Res and Elmer Press Inc

Journal website https://gr.elmerpub.com

Original Article

Volume 19, Number 2, April 2026, pages 100-109

Effectiveness of a Natural-Rubber Anal Dilator (ParaSelf) After Pediatric Anorectal Surgery: A Historical-Controlled Intervention Study

Figures

↓ Figure 1. Study flow diagram. HAEC: Hirschsprung-associated enterocolitis.

↓ Figure 2. (a) Normal and decubitus positions demonstrating the base (blue arrow). (b) Comparison with Hegar dilators of the same shaft diameter.

↓ Figure 3. (a) Lubricated rubber-based dilator. (b) The stopper positioned at the neck of the dilator, abutting the perianal skin to prevent over-insertion. (c) Comparison of dilator materials: paraffin-based dilator (yellow), metal-based dilator (silver), and plastic-based dilator (white).

↓ Figure 4. Weibull proportional hazard regression on time to reach target anal diameter.

Tables

↓ **Table 1.** Baseline Clinical Characteristics
Prognostic factors	ParaSelf (n = 33), n (%)	Conventional dilator (n = 65), n (%)	P value
HD: Hirschsprung disease; ARM: anorectal malformation; IQR; interquartile range.
Male	23 (69.7)	44 (67.7)	1.000
Age (month), median (IQR)	6 (1, 48)	23 (1, 45)	0.406
Weight (kg), median (IQR)	8 (4, 12)	8 (3, 12)	0.973
Anatomical subtype			0.755
Short type HD	15 (45.5)	31 (47.7)
Long type HD	5 (15.2)	13 (20.0)
Perineal fistula	7 (21.2)	7 (10.8)
Vestibular fistula	2 (6.1)	5 (7.7)
Rectourethral fistula bulbar	1 (3.0)	1 (1.5)
Rectourethral fistula prostatic	1 (3.0)	1 (1.5)
ARM without fistula	2 (6.1)	7 (10.8)
Initial anal diameter (mm), median (IQR)	12 (7, 14)	12 (9, 15)	0.128

↓ **Table 2.** Adjusted Risk Differences for Postoperative Endpoints
Endpoint	Clinimetric	Point estimate	95% CI	P value
CI: confidence interval; RD: risk difference; HAEC: Hirschsprung-associated enterocolitis.
Anal stenosis	RD	–0.34	–0.48, –0.21	< 0.001
Anal stenosis requiring surgery	RD	–0.08	–0.14, –0.02	0.011
Pain scale during self-dilation	Median difference	–2.58	–3.40, –1.76	< 0.001
Caregiver satisfaction	Median difference	2.00	1.52, 2.48	< 0.001
Anastomotic leakage	RD	–0.06	–0.11, –0.01	0.017
Bleeding	RD	–0.39	–0.53, –0.25	< 0.001
HAEC	RD	–0.16	–0.32, 0.00	0.057
Anal irritation	RD	–0.20	–0.30, –0.11	< 0.001