Open haemorrhoidectomy combined with lateral internal sphincterotomy versus conventional haemorrhoidectomy: a prospective randomized comparative study

Abstract

Background

Open haemorrhoidectomy is an effective treatment for haemorrhoidal disease, but it is associated with significant postoperative pain and early bleeding. Lateral internal sphincterotomy (LIS) has been recommended as an adjunctive procedure to reduce sphincter spasm and facilitate post-operative healing. This study was designed to compare postoperative pain and bleeding in patients treated with an open haemorrhoidectomy with or without a lateral internal sphincterotomy.

Methods

This prospective, randomized, comparative study was conducted at Baghdad Teaching Hospital from March 2024 to July 2025. A total of 120 patients with Grade III or IV haemorrhoids were randomly divided into two groups: the group of open haemorrhoidectomy with lateral internal sphincterotomy (Group A, n = 60) or the group of open haemorrhoidectomy alone  (Group B, n = 60). Allocation was made by means of sealed, opaque envelopes. Pain and postoperative bleeding were compared during the first 24 h, 48 h, one week and two weeks thereafter. Statistical analysis was carried out using the chi-square test or Fisher’s exact test, with p < 0.05 considered statistically significant.

Results

Postoperatively, patients who underwent haemorrhoidectomy and lateral internal sphincterotomy had significantly less pain during all assessed time points. At 1 week, 81.6% of patients in Group A were pain-free compared to none in Group B (risk difference 81.7%, 95% CI 71.9%–91.5%; p < 0.001). At 2 weeks, 94.2% in Group A were pain-free vs. 3.5% in Group B (risk difference 90.7%, 95% CI 82.8%–98.7%; p < 0.001).

Bleeding occurred in 5% of patients in Group A compared to 41.6% in Group B at 24 h (p < 0.001), and in 5% versus 35% at 48 h (p < 0.001). No further bleeding episodes were observed in Group A beyond the first postoperative week.

Conclusions

Inclusion of lateral internal sphincterotomy in the standard open haemorrhoidectomy decreases both postoperative pain and early bleeding, which leads to improved short-term recovery. This combination method seems to be a safe and efficacious modification of conventional haemorrhoidectomy.

Trial registration

This study was retrospectively registered at ClinicalTrials.gov on 13th January 2026. Identifier NCT07360912.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-026-03714-5.

Introduction

Haemorrhoidal plexuses are engorged vascular cushions present in the anal canal, which physiologically provide for continence [1, 2]. If the connective tissue that supports these cushions is weak, they become symptomatic, leading to venous congestion, prolapse, and discomfort [1]. Many factors have been implicated in the etiology of haemorrhoidal disease, including chronic straining, constipation, prolonged sitting, obesity, and age [3, 4]. Even though constipation and haemorrhoids are coexistent, their epidemiological profiles do not totally coincide, suggesting that the disease is multifactorial rather than having a single aetiology [1, 5].

Haemorrhoidal disease is a common condition, with a prevalence of up to 5% in the general population and over 50% after the age of 50 [6–8]. Although it is common, the rate of clinical presentation to healthcare services is low, as the majority of patients are asymptomatic or treated conservatively. Surgery is commonly indicated for more advanced disease or when non-operative therapy fails [9].

Open haemorrhoidectomy has remained the best surgery for patients with grades III and IV haemorrhoids [10, 11]. Nevertheless, it is often associated with considerable postoperative pain, slow recovery, and early post-operative bleeding that might be detrimental to patients’ subjective well-being and functional results [12]. Postoperative pain is mainly due to spasm of the internal anal sphincter and increased resting anal pressure after surgery [1, 13].

Lateral internal sphincterotomy (LIS) is a feasible adjuvant procedure that can reduce the hypertonicity of the internal sphincter, thereby reducing postoperative pain and promoting early recovery [14, 15]. By relaxing sphincter spasm, LIS can also reduce tension on the surgical wound, which may have implications for improved haemostasis and reduced postoperative bleeding [16, 17]. Although previous studies have shown a reduction in postoperative pain with LIS as an adjunct, the literature has been less consistent regarding early postoperative bleeding [16, 18, 19].

Accordingly, we sought to evaluate postoperative pain and bleeding among patients who underwent an open haemorrhoidectomy with or without lateral internal sphincterotomy (LIS) to ascertain whether there is any advantage or benefit of adding LIS in the initial period of recovery.

Methods

This is a prospective, randomized comparative study conducted at Baghdad Teaching Hospital from March 2024 to July 2025. The study was approved by the Ethical Committee of the College of Medicine, University of Baghdad (Approval No: 415, Date: 20 January 2024) and performed in accordance with principles in the Declaration of Helsinki. The study was retrospectively registered at ClinicalTrials.gov on 13 January 2026 (Identifier: NCT07360912) during manuscript preparation. Informed consent was obtained from all the participants after providing written information.

Patient selection

Patients between 18 and 70 years complaining of symptomatic Grade III or IV haemorrhoids, according to the Goligher classification, were considered for inclusion. A total of 150 (of the initial 180 patients) fulfilled inclusion criteria. Thirty patients refused to participate and 120 agreed and provided consent for inclusion in the study (Fig. 1).

Fig. 1.

Consort flow diagram showing patient assessment, eligibility, randomization, and follow-up. LIS: lateral internal sphincterotomy

Patients with concomitant anorectal pathologies (including anal fissure, fistula, inflammatory bowel disease or anorectal malignancy), a history of haemorrhoidectomy or significant comorbidities were excluded as well as pregnant patients.

Randomization and allocation concealment

Patients were randomly assigned to one of the two study groups using a computer-generated random sequence. Allocation was concealed using sequentially numbered, sealed, opaque envelopes that were prepared in advance by an independent assistant who was not involved in patient recruitment or surgical procedures.

After obtaining informed consent, each patient was allocated to a study group by opening the next envelope in sequence.

Group A (n = 60): Patients who underwent open haemorrhoidectomy combined with lateral internal sphincterotomy.

Group B (n = 60): Patients who underwent open haemorrhoidectomy alone.

Surgical technique

All operations were carried out under general anesthesia with lithotomy position. In order to maintain homogeneity, all procedures were performed by a single experienced surgeon.

Open haemorrhoidectomy was carried out using standard surgical instruments (scalpel, scissors, and diathermy) following established techniques [20]. The haemorrhoidal pedicles were dissected, ligated and excised, care was taken to preserve the external anal sphincter, and haemostasis was achieved using diathermy where required.

In Group A, after completing the haemorrhoidectomy, a lateral internal sphincterotomy was carried out under direct vision. The internal anal sphincter was identified and cut to about 1 cm up from the dentate line.

At the end of the procedure, the anal canal was packed with absorbable haemostatic gelatin, followed by sterile dressing of the perianal area and application of a T-bandage.

Postoperative care

Patients were given standard postoperative analgesia as per institutional policy including non-steroidal anti-inflammatory drugs, with additional analgesia administered as required.

Patients were advised to take warm sitz baths twice daily, starting on the second postoperative day, and after each bowel movement. Warm sitz baths with a little dissolved sodium chloride were given and continued for one week.

Outcome measures

The primary outcome was the proportion of patients who were pain-free at one week postoperatively. Pain was assessed using the Visual Analog Scale (VAS) (Fig. 2), ranging from 0 (no pain) to 10 (worst imaginable pain).

Fig. 2.

Visual analogue scale for pain (VAS)

Pain scores were categorized as follows:

• No pain = (0)

• Mild pain= (1–3)

• Moderate pain = (4–6)

• Severe pain = (7–10).

For the primary outcome analysis, patients were classified as pain-free (VAS = 0) or not pain-free (VAS > 0).

Pain assessments were recorded by trained nursing staff who were not involved in the surgical procedures. All patients received a standardized postoperative analgesic regimen in accordance with institutional protocols.

The secondary outcome was the occurrence of postoperative bleeding at 24 h, 48 h, 1 week and 2 weeks after surgery. Postoperative bleeding was defined as any clinically evident bleeding from the surgical site occurring during the postoperative period that required medical assessment, additional dressing, or prolonged observation. Minor bleeding was defined as self-limited bleeding not requiring intervention, whereas clinically significant bleeding referred to bleeding requiring medical evaluation or intervention.

Bleeding was assessed by the attending surgical team during hospitalization and at follow-up visits based on clinical examination and patient reporting.

Continence was assessed clinically during postoperative follow-up based on patient-reported symptoms, including any complaints of gas or stool leakage. No formal continence scoring system, such as the Wexner score, was used in this study.

Patients were typically discharged on the first postoperative day and were followed up on an outpatient basis. Follow-up assessments were conducted during scheduled clinic visits, and patients were also instructed to report any bleeding episodes. All reported events were confirmed by clinical evaluation when necessary.

Blinding

Blinding of the surgeon and patients was not feasible due to the nature of the surgical interventions. However, postoperative outcome assessment was performed by a clinician who was not involved in the surgical procedures, thereby reducing potential assessment bias.

Sample size calculation

Sample size was estimated prior to patient recruitment. Based on previously published studies, an improvement of approximately 25–30% in the pain-free rate (from about 50% to 75%) was expected with the addition of lateral internal sphincterotomy (LIS) [14, 15, 19].

The required sample size was calculated for comparison of two proportions, using a two-sided significance level (alpha) of 0.05 and a statistical power of 90%. This resulted in a minimum of 58 patients per group. To account for potential loss to follow-up, 60 patients were included in each group (total n = 120).

Statistical analysis

Data were analysed using IBM SPSS version 25. Continuous variables were expressed as mean ± standard deviation (SD), and categorical variables were presented as frequencies and percentages.

Data distribution was assessed using the Shapiro–Wilk test. Comparisons between groups were performed using the independent t-test for continuous variables and the chi-square test or Fisher’s exact test for categorical variables, as appropriate. Confidence intervals (95%) were calculated where appropriate. A p-value < 0.05 was considered statistically significant.

For the primary outcome, patients were categorized as pain-free (VAS = 0) or not pain-free (VAS > 0), and a binary comparison between groups was performed.

Results

Overall, 120 patients were enrolled, with each group comprising 60 patients. Group A included 39 (65%) male patients, and 21 (35%) females. Group B included 36 (60%) male patients and 24 (40%) females. In general, the study sample consisted of 75 males (62.5%) and 45 females (37.5%), with a male-to-female ratio of 1.67:1.(Table 1).

Table 1.

Sex distribution in studied groups

Sex	Group A (n= 60)	Group B (n= 60)	Total (n= 120)
Male	39 (65%)	36 (60%)	75 (62.5%)
Female	21 (35%)	24 (40%)	45 (37.5%)
Total	60	60	120

The ages of the patients were well matched in the two groups. In Group A, 13.3% of patients were between 20 and 30 years, 36.7% were between 31 and 40 years, 26.7% were between 41 and 50 years, and 23.3% of patients fell within the age range of 51 to 60 years old. In Group B, the numbers were 15.0%, 28.3%, 23.3%, and 33.3%. The average ages in Groups A and B were 41.4 ± 10.1 years and 42.9 ± 11.0 years, respectively (no significant difference between the two groups). These differences suggest that the two groups were highly similar in terms of basic demographic characteristics (Table 2).

Table 2.

Age distribution in the studied groups

Age (year)	Group A (n=60)	Group B (n=60)	Total (n=120)
20-30	8 (13.3%)	9 (15.0%)	17 (14.2%)
31-40	22 (36.7%)	17 (28.3%)	39 (32.5%)
41-50	16 (26.7%)	14 (23.3%)	30 (25.0%)
51->60	14 (23.3%)	20 (33.3%)	34 (28.3%)
Mean ±SD	41.4 ± 10.1	42.9 ± 11.0	42.2 ± 10.5
Total	60 (50.0%)	60 (50.0%)	120(100.0%)

Postoperative bleeding

Postoperative bleeding results are presented in Table 3. Patients in Group A showed significantly lower frequencies of early postoperative bleeding compared to those in Group B. In the first 24 h after surgery, bleeding occurred in 3 (5%) patients in Group A compared to 24 (41.6%) patients in Group B (p < 0.001). This difference remained significant at 48 h, with bleeding occurring in 3 (5%) patients in Group A and 21 (35%) patients in Group B (p < 0.001).

Table 3.

Postoperative bleeding in the studied groups

Bleeding	Group A	Group B	P value
24 h	3 (5%)	24 (41.6%)	p < 0.001
48 h	3 (5%)	21 (35%)	p < 0.001
1 week	0 (0%)	12 (20%)	p = 0.0008
2 week*	0 (0%)	2 (3.3%)	p = 0.52

* Percentages at two weeks are calculated based on the number of patients available for follow-up (group a = 52, group b = 57)

No additional bleeding episodes were observed in Group A after the first postoperative week, whereas 12 (20%) patients in Group B continued to experience bleeding (risk difference − 35.0%, 95% CI − 48.6% to − 21.4%; p = 0.0008). At two weeks, no patients in Group A had bleeding, while 2 (3.3%) patients in Group B still reported bleeding, which was not statistically significant (p = 0.52, 95% CI: −8.3% to 1.3% ).

Importantly, no patient in either group required blood transfusion or surgical intervention for postoperative bleeding.

Postoperative pain

Postoperative pain scores were significantly different in each group of patients, as demonstrated by a comparison between the two groups (Table 4), showing lower pain scores among patients who underwent haemorrhoidectomy with lateral internal sphincterotomy.

Table 4.

Postoperative pain in the studied groups

Pain	Category	Group A	Group B
24 h	No pain	20 (33.3%)	0 (0%)
	Mild	25 (41.7%)	8(13.3%)
	Moderate	12 (20.0%)	28(46.6%)
	Severe	3(5.0%)	10 (16.6%)
	Total	60	60
48 h	No pain	32 (53.3%)	10 (16.7%)
	Mild	21(35.0%)	18 (30.0%)
	Moderate	7 (11.7%)	22 (36.7%)
	Severe	0 (0%)	10 (16.7%)
	Total	60	60
1 week	No pain	49 (81.7%)	0 (0%)
	Mild	8 (13.3%)	25 (41.6%)
	Moderate	3 (5%)	22 (36.7%)
	Severe	0 (0%)	23 (38.3%)
	Total	60	60
2 weeks*	No pain	49 (94.23%)	2 (3.51%)
	Mild	3 (5.77%)	21 (36.84%)
	Moderate	0 (0%)	20 (35.09%)
	Severe	0 (0%)	14 (24.56%)
	Total	52	57

* Percentages at two weeks are calculated based on the number of patients available for follow-up (Group A = 52, Group B = 57)

For the primary outcome (pain-free at 1 week), patients were categorized as pain-free (VAS = 0) or not pain-free (VAS > 0).

24 hours

At 24 h postoperatively, 20 (33.3%) patients in Group A reported no pain, whereas none of the patients in Group B were pain-free 24 h postoperatively. Mild pain was significantly higher in Group A (41.7%) compared to Group B (26.6%). Moderate and severe pain were more prevalent in Group B compared to Group A (46.6% and 16.6%, vs. 20% and 5%). These differences were statistically significant.

48 hours

At 48 h, both groups still showed a reduction in pain; however, Group A experienced significantly better results. No pain was reported by 53.3% patients in Group A and 16.7% in Group B. Moderate and severe pain were still endured by 36.7% and 16.7% of patients in group B at time of evaluation, respectively; while these levels were either much lower or absent in group A (11.6% and 0% respectively).

One week

One week after the operation, most Group A patients (81.6%) reported being pain-free, (5%) experienced moderate and no patient experienced severe levels of pain. In contrast, most of the patients in Group B had mild (40%), moderate (41.6%), and severe (18.3%) pain. The risk difference was 81.7% (95% CI 71.9% to 91.5%; p < 0.001).

Two weeks

Pain data at 2 weeks was obtained from 52 patients in group A and 57 patients in group B, as the remaining patients were lost to follow-up and excluded from this analysis. The calculated percentages at this time were based on available data.

By the time of assessment, nearly all patients (94.2%) in Group A were pain free, and only 5.7% reported mild discomfort. In group B, 3.5% of patients reported no pain, while 36.8% and 35% of patients in group B reported mild and moderate degrees of pain, respectively (Table 4). Importantly, 24.5% still had severe pain, predominantly during defecation, with a risk difference 90.7% (95% CI 82.8% to 98.7%; and p < 0.001).

Patients undergoing haemorrhoidectomy with lateral internal sphincterotomy had less duration of pain persistence and analgesia requirement during the early postoperative period up to 2 weeks of follow-up in comparison to the patients who underwent haemorrhoidectomy alone.

Discussion

This prospective randomised study demonstrates that the addition of LIS to open haemorrhoidectomy is beneficial in improving early postoperative outcomes, significantly decreasing pain scores and early postoperative bleeding. The benefits were extended to all assessed intervals measured from 24 h to two weeks postoperatively, consistent with LIS serving as a valuable adjunct in early recovery from haemorrhoidectomy [16, 19].

Postoperative pain associated with open haemorrhoidectomy and its reduction seems to be crucial in achieving patient compliance and mutual satisfaction. Patients who underwent LIS had significantly lower resting anal sphincter pressure and by relieving internal sphincter spasm. LIS may aid in wound healing and reduce pain perception by decreasing sphincter hypertonicity, thereby enhancing local perfusion and reducing ischemia at the anorectum. These findings are in line with earlier studies demonstrating lower postoperative pain scores and reduced analgesic requirements when LIS is added to haemorrhoidectomy [21].

This study demonstrated a significant reduction in early postoperative bleeding in patients with LIS, particularly during the first week after surgery. This may be attributed to the decreased mechanical tension on the surgical wound after sphincter relaxation, resulting in more durable haemostasis. The pain results of LIS have been well documented in the literature, but few studies have described its effects on early postoperative bleeding. The present findings provide further evidence for the haemostatic benefit of LIS in the early postoperative phase.

Not all published studies have demonstrated a consistent advantage of LIS when performed routinely with haemorrhoidectomy, with some reporting no significant benefit in postoperative pain reduction [22]. Others have reported limited or no benefit to postoperative results, and concerns have been raised regarding the risk of continence. These variations may be attributed to differences in operative technique, sphincter division, post-operative pain management, and patient selection. A limitation of the present study during treatment is that LIS was administered by a single experienced surgeon under stringent control, which may have decreased procedural variability and contributed to the excellent outcomes.

No cases of clinically reported postoperative incontinence were observed during the follow-up period. However, continence assessment was based on patient-reported symptoms without the use of a validated scoring system, and the follow-up duration was limited to two weeks. Therefore, subtle or late-onset continence disturbances, particularly flatus incontinence, may not have been detected. This observation is in accordance with other studies that have indicated that an adequate and well monitored sphincterotomy does not cause risk of incontinence [17, 23]. However, patients need to be informed on the possible risk of temporary flatus incontinence, especially with LIS.

Conclusion

The benefits of adding lateral internal sphincterotomy to traditional open haemorrhoidectomy are decreased postoperative pain and early postoperative bleeding, which contribute to an enhanced short-term recovery. This technique appears to be a safe and efficient modification of conventional haemorrhoidectomy without increasing the incidence of complications. Lateral internal sphincterotomy should hence be especially advantageous for those patients at risk of a postoperative sphincter spasm and early severe pain.

Strengths and limitations

This study has several strengths, including its prospective randomized design, a relatively homogeneous patient population, and the use of a standardized surgical technique performed by a single experienced surgeon, which helped minimize inter-procedural variability. In addition, postoperative pain and bleeding were assessed at predefined time points using standardized measures, allowing for a consistent and reliable comparison between the two groups. However, some limitations must be highlighted. Performing all surgeries by a single surgeon may limit the generalizability of the findings to other clinical settings and surgeons with different levels of experience. It may also introduce a degree of performance bias, as individual surgical expertise can influence postoperative outcomes. Future multicenter studies involving multiple surgeons would be valuable to confirm these findings and improve external validity. Follow-up was limited to the immediate postoperative period, and long-term effects involving continence, anal stenosis, or recurrence were not studied. Finally, a few patients were lost to follow-up at two weeks and could have potentially introduced some bias. Indeed, with this sample size, the statistical power was sufficient to detect clinically essential differences in early postoperative results.

Authors’ contributions

Alaa Alsalaumy conceived and designed the study, performed the surgery, collected the data, conducted the statistical analysis, and drafted the manuscript.

Funding

This research received no external funding.

Data availability

The datasets generated and/or analysed during the current study are not publicly available due to institutional data protection policies but are available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

This study was approved by the Ethical Committee of the College of Medicine, University of Baghdad (Approval No: 415, Date: 20.01.2024), and was conducted in accordance with the Declaration of Helsinki. Written informed consent was obtained from all participants.

At the time of study initiation, prospective trial registration was not mandatory at our institution, and ethical approval was considered sufficient for conducting clinical research. Therefore, patient recruitment began prior to trial registration.

To comply with international publication standards and ensure transparency, the study was retrospectively registered at ClinicalTrials.gov (Identifier: NCT07360912) on 13 January 2026.

The study protocol, including all primary and secondary outcomes, was predefined before patient recruitment and was not modified after completion of the study.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.