Surgical management of anal stenosis following hemorrhoid treatment: a single-center case series

Abstract

Objective

To describe the clinical characteristics, causes, classification, and surgical techniques used to treat anal stenosis following hemorrhoid surgery, as well as to evaluate the treatment outcomes based on specific clinical criteria.

Subjects and methods

This retrospective case series included 13 patients with anal stenosis after hemorrhoidectomy. All underwent surgical treatment at Viet Duc University Hospital between January 2022 and June 2024. Surgical techniques applied were fibrotic ring release alone, fibrotic ring release with rectal mucosal advancement, fibrotic ring release with horizontal suturing of the rectal mucosa, and fibrotic ring release with V–Y flap reconstruction. Outcomes were assessed based on patients’ ability to achieve normal defecation, stool caliber, and the absence of anal pain or bleeding postoperatively. Successful treatment was defined as normalized stool passage without pain or the need for stool softeners.

Results

Surgical outcomes were favorable in 12 out of 13 patients (92.3%), with an average healing time of 2.0 ± 1.1 months. The mean follow-up was 13.3 months (range 6–24 months; minimum 6 months). Patients treated with fibrotic ring release alone experienced the longest healing time, while those who underwent mucosal advancement or V–Y flap reconstruction had shorter recovery periods. Recurrence occurred in one patient who required reoperation.

Conclusion

Anal stenosis is a rare but serious complication following hemorrhoid surgery. Surgical interventions, including fibrotic ring release and anoplasty, appeared to be effective and safe, with favorable short-term outcomes in most patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00384-026-05105-x.

Introduction

Anal stenosis is a recognized complication following hemorrhoid surgery [1]. Symptoms include difficulty in defecation, anal pain, and reduced stool caliber, which can be unresponsive to stool softeners and dietary modification [2]. Although uncommon, anal stenosis remains a significant postoperative complication. Approximately 90% of cases occur following excessive hemorrhoidectomy, particularly with the Whitehead procedure [3]. In contrast, hemorrhoidectomy techniques such as Milligan-Morgan or Longo (stapled hemorrhoidopexy) are associated with lower rates of stenosis, ranging from 0.8% to 6% [4]. Excessive excision of perianal mucosa and skin without adequate preservation of tissue bridges can lead to chronic scar formation and progressive stenosis. Anal stenosis is classified as mild, moderate, or severe and may involve the anal canal segmentally or diffusely [5].

Management of anal stenosis ranges from conservative medical treatments to surgical interventions and is tailored to the degree of stenosis and the level of symptomatology. Mild stenosis can be treated with stool softeners, fiber supplements, and manual or mechanical dilation. Partial internal sphincterotomy may be indicated in mild cases. For more severe stenosis, surgery is warranted. Various surgical techniques, including fibrotic ring release and anorectal reconstruction—with or without the use of flaps—are employed to address anal stenosis [6]. Common postoperative complications associated with these procedures include wound infection, ischemia, and bleeding. While anal stenosis has been reported in several international series, most available data come from Western centers. Evidence from Southeast Asia is scarce, and no systematic study has been published from Vietnam. Viet Duc University Hospital, as one of the largest tertiary referral centers, frequently manages patients with severe post-hemorrhoidectomy stenosis. Presenting our experience therefore provides important regional evidence and contributes to the global understanding of this condition.

Materials and methods

Study design

This study is a retrospective descriptive case series including all consecutive patients who developed anal stenosis following hemorrhoid surgery and subsequently underwent surgical treatment at Viet Duc University Hospital between January 2022 and June 2024. All patients were followed until June 2024 or until recurrence was clinically confirmed. Patient data were obtained from the institutional surgical logbook and electronic medical records to ensure completeness and minimize selection bias. Descriptive statistics were used to summarize the data. Continuous variables are presented as mean ± standard deviation (or median (range), where appropriate), and categorical variables as number (percentage). This study was reported in accordance with the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement. Ethical approval for this study was obtained from the Viet Duc University Hospital Ethics Committee, approval number 763/QĐ-VĐ.

Inclusion criteria

Patients diagnosed with and surgically treated for anal stenosis following hemorrhoid surgery at Viet Duc University Hospital. Patients with mild or moderate stenosis were initially managed conservatively with dietary modification, stool softeners, and progressive anal dilatation. Surgical intervention was indicated only when these measures failed to relieve symptoms.

Exclusion criteria

Patients with acute anal stenosis, those managed conservatively, cases of stenosis resulting from perineal trauma, congenital anorectal malformations, anastomotic strictures following cancer surgery, and patients with incomplete medical records were excluded from the study.

Surgical techniques

Four main surgical techniques were employed to address anal stenosis based on the severity and extent of the condition:

1. Fibrotic ring release alone

2. Fibrotic ring release with rectal mucosal advancement

3. Fibrotic ring release with horizontal suturing of the rectal mucosa

4. Fibrotic ring release with V–Y flap reconstruction

Each technique was chosen to address specific types and degrees of stenosis, considering the location and severity of the condition and surgeon’s preference.

Outcome criteria

The primary outcome measures included the restoration of normal stool caliber, absence of pain during defecation, lack of rectal bleeding, and no dependence on stool softeners post-treatment. Success was defined by the achievement of these outcomes, indicating a return to normal bowel function. All patients were examined in person after surgery until they were clinically stable. Thereafter, telephone interviews were used for extended follow-up to monitor for late complications or recurrence.

Results

From January 2022 to June 2024, 13 patients underwent surgery for anal stenosis following hemorrhoid treatment. The mean age was 45.2 ± 10.1 years (range 21–77), with a male-to-female ratio of 8:5. All patients (100%) presented with difficulty defecating and narrow stools. Eight patients (61.5%) reported defecation-associated pain, and six patients (46.2%) experienced rectal bleeding. The duration of symptoms is shown in Table 1. The extent and anatomical position of the stenoses are shown in Table 2. The types of original hemorrhoid surgery are shown in Fig. 1.

Table 1.

Time of symptom onset

Duration	N	%
< 4 months	8	61.5
7 months	1	7.7
1 year	1	7.7
> 2 years	3	23.1

Table 2.

Classification of anal stenosis by severity and height

Severity	N	%
Mild	1	7.7
Moderate	3	23.1
Severe	9	69.2
Location	N	%
High	1	7.7
Intermediate	1	7.7
Low	9	69.2
Diffuse	2	15.4

Fig. 1.

Types of original hemorrhoid surgery in patients who later developed anal stenosis

Surgical techniques of repair included the following: fibrotic ring release alone, fibrotic ring release with rectal mucosal advancement, fibrotic ring release with horizontal suturing of the rectal mucosa, and fibrotic ring release with V–Y advancement flap [7–9] (Table 3). The mean follow-up was 13.3 months (range 6–24 months; minimum 6 months). Overall, 12/13 patients (92.3%) achieved treatment success; 1/13 (7.7%) experienced recurrence. Postoperative healing rates according to the type of surgical technique are shown in Fig. 2. The fibrotic ring release combined with rectal mucosal advancement had a healing rate of 83%, while all other techniques—including fibrotic ring release alone, horizontal suturing of the rectal mucosa, and V–Y advancement flap—achieved 100% clinical healing.

Table 3.

Surgical method and duration

Surgical method	N	%	Duration (minutes)
Fibrotic ring release	4	30.8	37 ± 10
Fibrotic ring release with rectal mucosal advancement	6	46.2	57 ± 20
Fibrotic ring release with horizontal suturing of the rectal mucosa	1	7.7	60
Fibrotic ring release with V–Y flap reconstruction	2	15.4	104 ± 5

Fig. 2.

Postoperative healing rates according to surgical technique

Discussion

Anal stenosis is an uncommon but significant complication following hemorrhoidectomy, primarily resulting from the removal of excessive perianal skin and mucosa, which leads to chronic fibrosis and progressive narrowing of the anal canal. In our study, all 13 patients (100%) presented with defecation difficulty and narrowed stool caliber, with nearly half experiencing anal pain and rectal bleeding. This aligns with previous studies reporting that anal stenosis often manifests with a combination of defecation difficulty, anal pain, and bleeding [5].

In terms of etiology, our findings are consistent with international literature. A majority of cases in our study developed after surgical hemorrhoid treatments, specifically the Milligan-Morgan hemorrhoidectomy, HCTP (high-frequency capacitance pile treatment), and Longo procedures. This is in line with Gallo’s systematic review of 556 cases, which highlighted that hemorrhoidectomy is a primary contributor to anal stenosis, accounting for over three-quarters of cases [8]. Notably, we observed no cases of stenosis following the Whitehead procedure, which is known to have the highest stenosis rate in global studies [3]. This likely reflects reduced use of the Whitehead method due to its high risk of complications.

The classification of stenosis in our study revealed that severe stenosis was the most prevalent, occurring in 69.2% of cases. This distribution contrasts with the findings by Yu-Tse Weng et al. who reported a lower incidence of severe stenosis and a higher incidence of mild stenosis [10]. The discrepancy may be due to our hospital’s tertiary care nature, which often results in the referral of more advanced cases. Additionally, cultural factors and limited health awareness in Vietnam might contribute to delayed diagnosis and treatment, resulting in more severe presentations.

Surgical techniques play a pivotal role in treating anal stenosis, with the choice of procedure tailored to the severity and location of the narrowing. In our cohort, fibrotic ring release was the base procedure, supplemented by rectal mucosal advancement or V–Y flap reconstruction in more complex cases. These approaches were selected not only to relieve the physical obstruction but also to restore mucosal continuity and functional integrity, which are crucial for long-term success. The V–Y flap technique, while effective in providing additional mucosal coverage, was associated with a minor complication of flap dehiscence in one patient. Importantly, no major complications such as abscess or infection were observed, reflecting the high safety profile of these methods. Based on our limited institutional experience, mucosal flap advancement appeared feasible, but these observations should be interpreted with caution as further studies are needed.

Although surgery is not usually the first choice for mild or moderate anal stenosis, the four patients in our cohort with these grades had persistent symptoms despite conservative management. They continued to report obstructed defecation and pain and therefore underwent surgery. Two patients received fibrotic ring release with rectal mucosal advancement, while the other two underwent V–Y flap anoplasty. This approach reflects the principle that surgery is considered when conservative measures fail to provide adequate relief.

Our recurrence rate was 7.7% (1/13 patients), which is comparable to the 9.5% reported by Weng et al. after scar revision and consistent with their 0% recurrence rate following anoplasty [10]. By contrast, Habr-Gama et al. reported no recurrence in their series of 77 patients treated with sliding flap anoplasty, with a 1-year success rate of 87% and a mean healing time of 3–6 weeks [6]. Healing time in our cohort averaged 2.0 ± 1.1 months, which is slightly longer but within the expected international range. In terms of complications, only one case of minor flap dehiscence occurred in our study, which is similar to the single case of suture line dehiscence reported by Habr-Gama, and lower than the 3–10% complication rates summarized by Brisinda et al. across various anoplasty techniques [6, 7]. Taken together, these comparisons demonstrate that our outcomes are consistent with international experience, despite the predominance of severe stenosis (69.2%) in our cohort, which reflects the referral bias of a tertiary care center.

The postoperative management included regular anal dilation and the use of stool softeners, particularly for patients who underwent fibrotic ring release alone. Dilation was effective in maintaining luminal patency and minimizing scar contraction, which has been supported by findings from Brisinda et al. who recommended dilation as an adjunctive measure in postoperative care [7]. Our follow-up period of 13.3 months showed a success rate of 92.3%, with one patient initially stable after surgery but later missing scheduled visits. This patient subsequently returned with recurrent symptoms, which were clinically confirmed and required reoperation. This recurrence rate aligns with findings by Habr-Gama et al. who reported similar success rates with anal mucosal advancement and V–Y flap procedures [6].

This study has several limitations. First, the retrospective design and small sample size limit the generalizability and statistical power of the findings. Second, although all patients were re-examined in person after surgery until clinical stabilization, subsequent follow-up relied partly on telephone interviews. This method may introduce reporting bias, particularly for subjective outcomes such as stool caliber and anal pain. Third, the definition of treatment success was based on clinical improvement without stool softeners, without incorporating validated functional scoring systems. Future studies should employ standardized instruments, such as the Wexner or Cleveland Clinic Incontinence Score (CCIS), to allow a more objective assessment of anorectal function. Finally, the use of the Milsom classification, which has not been formally validated, may limit reproducibility across different centers. Prospective studies with larger cohorts, longer follow-up, and validated outcome measures are needed to confirm these preliminary findings.

Conclusion

Anal stenosis remains a challenging postoperative complication. Modern surgical techniques such as fibrotic ring release and V–Y flap reconstruction appear to achieve favorable outcomes with low recurrence in selected cases. As recurrence may occur after simple release procedures, the choice of reconstructive technique should be individualized based on the severity and extent of stenosis. The present study adds regional data to existing literature and may help guide colorectal surgeons in selecting appropriate, patient-specific approaches for this complex condition.

Supplementary Information

Below is the link to the electronic supplementary material.

Author contributions

Pham Phuc Khanh and Do Tat Thanh wrote the main manuscript text. Nguyen Thi Thanh Huyen, Nguyen Thi Ly, Le Nhat Huy, Nguyen Dac Thao, and Rickard Mathew contributed to data interpretation, reviewed the manuscript, and provided critical feedback. All authors reviewed and approved the final version of the manuscript.

Funding

This research received no external funding.

Data availability

The datasets generated and/or analyzed during the current study are not publicly available due to patient confidentiality but are available from the corresponding author on reasonable request.

Declarations

Competing interests

The authors declare no competing interests.