Anorectal changes and clinical outcomes after the Duhamel operation

Abstract

BACKGROUND

Surgery for Hirschsprung’s disease (HD) generally results in a satisfactory outcome, but some patients continue to have bowel dysfunction. There are very few studies in the literature that compare the early and late clinical outcomes.

AIM

To evaluate changes in anorectal function and clinical outcome with age in patients who underwent Duhamel operation (DO) for HD.

METHODS

Twenty-eight patients who had previously undergone DO to treat HD were invited to an outpatient clinic upon reaching adulthood to participate in follow-ups. The patients’ clinical data from the early and mid-term follow-ups were evaluated retrospectively based upon the hospital records and datasets from previous studies. The functional outcome tests in adulthood included anorectal manometry, rectoanal inhibitory reflex, maximum anal resting pressure, and a questionnaire.

RESULTS

Among the patients that reached adulthood and underwent early and mid-term evaluations, only 10 responded to the invitation and attended. That study population was comprised of 8 males and 2 females, ranging in age from 19 years to 25 years, with an average of 21.57 years. The anorectal inhibitory reflex was abnormal in 6 of the patients (66.7%). While the rate of patients who were deemed clinically “good” at the early postoperative evaluation was 53%, that rate reached to 90% in the adult evaluation.

CONCLUSION

Improvement correlated with age, while other anorectal manometric parameters were unchanged. Long-term adult follow-up is essential for objectively evaluating surgical outcomes and overall success.

Key Words: Hirschsprung’s disease; Duhamel operation; Constipation; Enterocolitis; Children

Core Tip: Long-term clinical improvement after the Duhamel operation for Hirschsprung’s disease is dependent on age. Improvement occurs despite persistent manometric abnormalities. We recommend continued adult follow-up for objective outcome assessment.

INTRODUCTION

Hirschsprung’s disease (HD) is defined as a disorder of the enteric nervous system and occurs in approximately 1 in 5000 live births[1]. The absence of ganglion cells in the submucosal and myenteric plexuses, which is the underlying pathology, is due to the disrupted migration of neural crest cells. Although many surgical techniques have been described for treatment, anatomic involvement and surgeon experience are the determining factors[2].

The functional outcome in patients treated for HD is variable[1-4]. Despite reported favorable results after surgical treatment, long-term functional issues like constipation, recurrent enterocolitis, and fecal incontinence may occur[3,4]. There have been many publications on the long-term results of HD. It has been emphasized in many of the case series that bowel dysfunction complaints seen after definitive surgery regress with age[5-8]. However, there remains a lack of information in the literature regarding the outcome of bowel dysfunction problems of these patients in adulthood. Data on changes in anorectal function over time, obtained through repeated anorectal manometry examinations, can provide important insights into HD[9,10]. In this study, we aimed to evaluate age-related changes in anorectal function and clinical outcomes in patients who had undergone a Duhamel operation (DO) for HD, and to compare the short- and mid-term results of these patients with those from adulthood.

MATERIALS AND METHODS

Study design and setting

This was a retrospective cohort study comparing early, mid-term, and adult anorectal functions and clinical outcomes of patients who had undergone Duhamel surgery for HD between 2000 and 2003 in our clinic.

Patient selection and surgical technique

All patients had undergone the following standardized three-stage procedure: Initial colostomy, Duhamel pull-through operation, and colostomy closure. The diagnosis of HD was confirmed by rectal biopsy, and the extent of aganglionosis was determined intraoperatively using frozen-section analysis of serial seromuscular biopsies. The initial cohort included 28 patients, of whom 22 were re-evaluated during mid-term follow-up and 10 during adulthood.

Data collection and clinical evaluation

The patients' current symptoms, anorectal function, and clinical outcomes were assessed during follow-up via anorectal manometry and a structured questionnaire. The questionnaire, based on Farrugia et al[11], evaluated stool frequency and consistency, continence and incontinence, medication use, constipation, and episodes of enterocolitis.

Fecal incontinence was defined as regular involuntary passage of stool, whereas soiling was defined as occasional smearing without full loss of control. Constipation was defined as fewer than three spontaneous bowel movements per week, painful defecation, evidence of rectal impaction, or palpable fecal mass on examination[12]. Enterocolitis was diagnosed based on the presence of abdominal distension, diarrhea (with or without blood), vomiting, and fever.

Clinical outcomes were classified as: Good, fewer than two episodes of soiling per month and no constipation; moderate, soiling more than twice per week; or poor, persistent constipation, severe fecal incontinence, or recurrent enterocolitis.

Anorectal manometry procedure

All patients underwent anorectal manometry in the left lateral decubitus position. Maximum anal resting pressure (MARP) and the rectoanal inhibitory reflex (RAIR) were measured. RAIR was considered present if the anal sphincter pressure decreased by more than 20 mmHg following balloon inflation with 30 mL air.

Follow-up and longitudinal comparison

Anorectal manometry findings and bowel function questionnaire results were compared across the following three time points, to evaluate longitudinal changes: Early postoperative, mid-term, and adulthood. For patients with persistent or recurrent symptoms, possible anatomical causes (e.g., anastomotic stricture, residual aganglionosis) were ruled out by digital rectal examination, contrast enema, and confirmatory rectal biopsies.

Statistical analysis

MARP results were compared across age groups using analysis of variance. Clinical improvement and functional scores were compared using the χ² test. A P value < 0.05 was considered statistically significant.

Ethics approval

This study was conducted in accordance with the Declaration of Helsinki and approved by the local Ethics Committee (July 30, 2025). Given the retrospective nature of the study, no additional written consent was required for inclusion.

RESULTS

Patient demographics and surgical details

A total of 28 patients (23 males and 5 females) were identified who had undergone DO between 2000 and 2003, with a mean age of 26.71 ± 12.99 months (range: 12-108 months). Twelve patients had presented as neonates, and sixteen had presented between 3 months and 5 years of age. The aganglionic segment had been rectosigmoid in 21 cases and long colonic in 7 cases.

Early postoperative outcomes

Postoperative enterocolitis had been observed in 5 patients (17.8%) after the definitive procedure. Persistent constipation had been reported in 7 patients (25%).

Anorectal manometry findings

First manometry (early period): Testing had been conducted in 28 patients (mean age: 4.46 ± 1.79 years). RAIR was absent in 23 patients (82%) and suspiciously positive in 5 patients. Mean MARP was 58.94 ± 13.39 mmHg. Clinical evaluation was “good” in 15 patients (53.6%).

Second manometry (mid-term): Testing had been conducted in 22 patients (mean age: 6.7 ± 1.56 years). RAIR was absent in 21 cases (95%). Mean MARP was 57.35 ± 13.04 mmHg. Clinical evaluation was “good” in 20 patients (90%).

Third manometry (adult period): Testing had been conducted in 10 patients (mean age: 21.55 ± 1.87 years). RAIR was present in 30% of cases. Mean MARP was 53.65 ± 16.72 mmHg. No patients were classified as clinically “poor”, 9 patients (90%) were classified as “good” and 1 patient (10%) as “moderate” (Table 1).

Table 1 Manometric and clinical results of patients experiencing Duhamel operation due to Hirschsprung’s disease (n = 28, 23 males and 5 females), n (%).

Postoperative gut function parameter	Postoperative 1 evaluation1	Postoperative 2 evaluation2	Postoperative 3 evaluation3
MARP in mmHg	58.94 ± 13.39 (range 35-92)	57.35 ± 13.04	53.65 ± 16.72 (range 34-81)
RAIR	23 (-)/5 (+)	21 (-)/1 (+)	7 (-)/3 (+)
Constipation	7 (25)	4 (18)	1 (10)
Soiling	8 (28.5)	4 (18)	1 (10)
Enterocilitis	5 (17.8)	1 (4.5)	-
Incontinance	2 (7.1)	-	1 (10)
Clinical follow-up
Good	15 (53.6)	20 (90)	9 (90)
Moderate	8 (28.6)	-	1 (10)
Bad	5 (17.8)	2 (10)	-

¹Age range: 3.2-7.8 years, mean 4.46 ± 1.79 years.

²Age range: 5.2-9.6 years, mean 6.7 ± 1.56 years.

³Age range: 19-25 years, mean 21.55 ± 1.87 years.

MARP: Maximum anal resting pressure; RAIR: Rectoanal inhibitory reflex.

Complications and additional interventions

In total, 4 patients (including 1 in the early period) had required surgery for adhesive small bowel obstruction during follow-up. Rectal biopsy had been repeated in 1 patient with persistent constipation and enterocolitis; the biopsy had revealed aganglionosis, and the patient had undergone a Swenson procedure subsequently.

Constipation and enterocolitis trends

Constipation rates decreased from 25% in the early evaluation period to 18% at the mid-term follow-up and 10% in adulthood. Enterocolitis incidence decreased from 17.8% in the early postoperative period to 4.5% at the mid-term follow-up, with no episodes in adulthood. Abdominal distension was noted in 2 adult patients.

Statistical comparisons

Comparative analysis of early, mid-term, and adult follow-ups revealed no statistically significant differences in continence, incontinence, medication usage, constipation, or enterocolitis (P > 0.05). Significant differences were found, however, between the early and adult periods regarding sensation of the need to defecate (P = 0.044), ability to postpone defecation (P = 0.028), and use of medication (P = 0.030; Table 2). Neither the MARP values (P = 0.789) nor RAIR presence (P = 0.559) showed statistically significant differences in comparisons across follow-up periods. In contrast, the clinical outcome classifications did differ in statistically significant manners across the three follow-up periods (P = 0.004).

Table 2 Parameters with significant improvement in the adult patient group, n (%).

Clinical follow-up evaluation parameter	Early period	Adult period	P value
Sensation of defecation	5 (50)	9 (90)	0.044
Ability to postpone defecation	4 (44.4)	9 (90)	0.028
Medication-free patient	3 (30)	10 (100)	0.030

DISCUSSION

Bowel functions are reported to be good in many HD cases after reconstructive surgery. Still, bowel dysfunction, such as enterocolitis, soiling, or constipation, may persist to varying degrees in the long term[12-14]. Long-term functional results may vary depending on the preferred pull-through technique that had been applied as well as the surgeon's experience[15,16]. Studies comparing the short-, medium-, and long-term outcomes among the same patient group treated with the same surgical technique are lacking in the literature. Therefore, reporting the short-, medium-, and long-term results of the patients is an important feature of the presented study.

Studies have yielded conflicting results regarding long-term functional bowel outcomes. As such, there is no clear information in the literature regarding the factors that may be responsible for the improvement or deterioration in bowel function with age. Detailed questionnaire results regarding bowel and urinary functions were reported by Davidson et al[12]. As a result, functional bowel impairments have been reported to improve with age[12,17,18]. In contrast, however, the evidence reported in past articles that had suggested no improvement in bowel function with age remain viable[14].

Anorectal manometry has become widely applied in efforts to elucidate long-term complications that develop after surgery, but publications are reporting that manometric studies may not be compatible with the patients’ full clinical profiles[8,9]. Explanations for the inconsistency between manometric and clinical findings include significant variability in terminology and definitions, manometry protocols, and quantitative criteria[9].

It is reported that RAIR is absent in HD patients and improves after surgery[19]. Although there are sufficient studies in the literature regarding postoperative RAIR, none have found a significant statistical correlation with clinical findings[20-22]. Similar to the debates over the definition and terminology of anorectal manometry noted earlier, the reported presence or absence of RAIR may be more related to the disparate criteria used to define it than to a genuine absence. As in the literature, the function of the rectum was evaluated in this study via anorectal manometry performed at regular intervals during the follow-up of the operated cases. There was no difference found between the groups regarding the MARP and RAIR in the structured measurements. Although it was stated that RAIR returned to normal after rectal pull-through surgeries, manometry revealed the anal sphincter not relaxing in the absence of RAIR in most of our patients. Furthermore, the manometric findings did not correlate with the clinical condition, and functional and clinical improvements were noted in adulthood.

We found a significant difference between the early and late assessments in terms of feeling of using the toilet, ability to postpone the need to toilet, and any medication use was not surprising. Since the early assessment is typically made at an average age of 4.6 years after toilet training is completed, it is expected that results of the assessments regarding toilet habits change with age and that a more regular defecation habit develops. The use of stool softeners, laxatives, or rectal enemas, which are more commonly used during the early period, decreases with age, and defecation can be performed without the need for any medication support. The absence of any changes in the repeated anorectal manometry evaluation suggests that clinical improvement is due to mechanisms other than anal sphincters. Completing the maturation of ganglion cells between the ages of 2 years and 4 years may lead to improvements in intestinal motility, as well as the voluntary use of abdominal muscles and learning to control the external anal sphincter, which becomes essential in the control of defecation with age.

The major limitation to this study is its retrospective nature. Another limitation is restricted attendance of adult patients to follow-up (35%). This study demonstrated that while the majority of patients had experienced impaired bowel function in the early postoperative period, significant clinical improvement had occurred over time and continued into adulthood. Despite persistent abnormalities in anorectal manometric parameters, the patients appeared to compensate through voluntary control of the abdominal muscles and relaxation of the external anal sphincter. These findings highlight that clinical improvement is largely age-dependent and not necessarily correlated with manometric changes, suggesting that the maturation of bowel function and the development of learned voluntary control play key roles in long-term recovery. This underscores the importance of long-term follow-up and tailored management strategies focusing on functional adaptation in patients treated surgically for HD. By prospectively following up all operated patients, it will be possible to uncover the changes in clinical findings of patients with HD treated with the DO more clearly and in detail.

CONCLUSION

Despite the retrospective design and restricted attendance of adult patients to follow-up (35%), this study demonstrates that while the majority of patients experience impaired bowel function in the early postoperative period, significant clinical improvement occurs over time and continues into adulthood. Despite persistent abnormalities in anorectal manometric parameters, our patients appeared to compensate through voluntary control of the abdominal muscles and relaxation of the external anal sphincter. These findings highlight that clinical improvement is largely age-dependent and not necessarily correlated with manometric changes, suggesting that the maturation of bowel function and the development of learned voluntary control play key roles in long-term recovery. Ultimately, this underscores the importance of long-term follow-up and tailored management strategies focusing on functional adaptation in patients treated surgically for HD. By prospectively following up all operated patients, it will be possible to gain substantive insights into the changes in clinical findings of patients with HD treated with the DO from childhood through adult age.