This single-institution case series adds to the limited literature on patients with coexisting achalasia and obesity who undergo treatment for both conditions. Our findings suggest that the timing of interventions whether achalasia is managed before, after, or concurrently with bariatric surgery and can influence outcomes, particularly symptom control, complication rates, and weight loss trajectories.

The interplay between obesity and EMDs and achalasia has been increasingly recognized, with studies estimating that esophageal motor abnormalities may be present to some degree in over half of patients with severe obesity [9]. Although the prevalence of achalasia in this population remains low (0.5–1%) [10], this likely reflects underdiagnosis due to symptom overlap, diagnostic challenges, and low clinical suspicion. In our cohort, patients presented with classic achalasia symptoms, dysphagia (82.4%), regurgitation (58.8%), and chest pain, mirroring prior reports in post-bariatric populations [16, 17]. Type II achalasia was the most frequent subtype, consistent with earlier studies [8]. Stratifying patients into each group revealed differences in outcomes, though our sample size limits definitive conclusions.

In our AF group, consistent with established literature, patients who underwent Botulinum toxin injection or pneumatic dilation often required further interventions, as these patients experienced symptom relapse requiring retreatment. Esophageal myotomy, whether accomplished laparoscopically or endoscopically, demonstrated better long-term symptom relief with initial clinical success rates exceeding 85–90%, supporting POEM and HM as effective treatment options for this population. Importantly, the need for additional endoscopic or surgical interventions in some patients reflects the chronic and relapsing nature of the disease rather than technical failure alone, particularly in the context of long-term follow-up and complex foregut anatomy [8, 18,19,20]. Subsequent bariatric surgery was feasible, though its complexity varied based on the prior achalasia procedure. RYGB after POEM was generally straightforward due to minimal adhesions, whereas RYGB following HM was more technically challenging due to prior fundoplication or hiatal scarring. Despite this, AF group achieved favorable weight loss (%TWL 20.2–33.9% at 12 months, 18–56.3% long term) and sustained symptom relief. These results support addressing achalasia prior to bariatric surgery to optimize esophageal function and reduce procedural risk. RYGB is typically favored for its superior reflux control [9, 13], though SG remains appropriate in select patients depending on GERD severity, comorbidities, and weight loss goals.

Conversely, outcomes in the BF group were more heterogeneous and recurrence is common. Since more than half of individuals with obesity and EMDs are asymptomatic, and preoperative esophageal testing is infrequently performed, it often remains unclear whether conditions such as achalasia are pre-existing or develop de novo following bariatric surgery. Our findings reinforce the importance of a low threshold for esophageal motility evaluation in bariatric candidates with dysphagia or reflux symptoms. This diagnostic uncertainty, combined with the lack of clear management guidelines, makes treatment in this population particularly challenging [3, 16, 21]. In our BF group, some patients initially underwent endoscopic therapies such as botulinum toxin injection or pneumatic dilation as temporizing measures, while others required definitive surgical intervention. Several patients experienced recurrent or refractory symptoms, with a higher incidence of re-intervention for achalasia or surgical revision likely reflecting the technical complexity of managing achalasia or EMDs after prior bariatric surgery and altered foregut anatomy. These findings are consistent with the case series by Crafts et al., but contrast with earlier case reports and small series in which most post-bariatric achalasia patients (n = 37) achieved symptomatic relief after interventions such as HM or POEM, with only two cases progressing to esophagectomy. Notably, the mean follow-up duration in those studies was limited (11.5 months), potentially underestimating long-term complications and treatment failures that we were able to capture in our cohort [9]. A previous study from our institution by Boules et al. identified 10 patients who developed achalasia following bariatric surgery, including eight who had undergone RYGB and two who had vertical banded gastroplasty (VBG). The median interval between bariatric surgery and the diagnosis of achalasia was six years. All patients underwent definitive surgical management: HM was performed in the RYGB group (n = 8), while both patients with VBG required esophagectomy due to end-stage disease. Most patients experienced symptomatic resolution following intervention.

Both POEM and HM are acceptable primary treatment modalities in this setting. POEM offers several potential advantages over HM, including the absence of abdominal incisions, shorter recovery time compared to laparoscopic surgery, and the ability to perform a longer myotomy with greater technical ease. However, HM offers the benefit of concurrent antireflux procedures and potentially lower long-term reflux risk. Across multiple small studies, POEM demonstrated high clinical success rates in treating achalasia after gastric bypass surgery and most patients experienced symptom relief, as evidenced by significant reductions in Eckardt scores, with low complication rates [22, 23]. HM can be technically challenging in patients with prior bariatric surgery due to intra-abdominal adhesions and altered anatomy, including the lack of the gastric fundus to perform a fundoplication. Nevertheless, successful outcomes with favorable symptom relief have been reported in post-bariatric surgery patients, including those with RYGB, across multiple case series [9].

Hiatal hernia status plays an important role in procedural planning for patients with a history of SG or RYGB. In RYGB patients, either POEM or HM combined with hernia repair is considered appropriate. For those with prior SG, the severity of GERD guides the management approach. Patients with severe reflux may benefit from conversion to RYGB along with myotomy and hernia repair. Slack et al. [24] reported such a strategy in a complex case involving conversion, POEM, and hernia repair.

In our BF group, GERD prevalence was higher in SG patients than in those undergoing RYGB (100% vs. 50%), and all SG patients ultimately required conversion to RYGB alongside achalasia treatment (via POEM or HM). This aligns with prior studies demonstrating that SG is associated with reduced LES pressure, impaired peristalsis, and increased reflux, whereas RYGB improves reflux with minimal impact on motility [25]. Naik et al. reported higher rates of GERD and motility disorders, including de novo achalasia, following SG and laparoscopic adjustable gastric banding (LAGB), with RYGB appearing protective [26]. Moreover, emerging data using EndoFLIP™ technology suggest higher rates of secondary esophageal motility disorders following SG and revisional bariatric procedures, with RYGB associated with comparatively lower physiological disruption [17]. In our series, EMDs were identified significantly earlier following SG compared to RYGB (6.0 vs. 19.8 years), suggesting that SG may accelerate or unmask dysmotility due to its restrictive, high-pressure design [13, 27]. Pseudoachalasia-like syndromes after bariatric surgery have also been described, often related to mechanical or anatomic factors despite normal integrated relaxation pressure (IRP) [28]. Expanding on these findings, Miller et al. reported a large retrospective study identifying manometric achalasia in 7.2% of post-bariatric patients and a newly described entity, POSED, in 5.2%. Notably, neither condition was observed in preoperative controls, and both demonstrated a time-dependent relationship, with symptoms developing up to 15 years after surgery [13]. These observations highlight the importance of careful diagnostic evaluation in bariatric patients with persistent dysphagia or reflux symptoms. Long-term follow-up and diagnostic workup, including upper endoscopy, contrast imaging, and esophageal function testing, should be considered to exclude pseudoachalasia. When pseudoachalasia cannot be clearly distinguished from true achalasia or other esophageal motility disorders, definitive achalasia-directed treatment may still be required.

Only one patient underwent concurrent treatment (HM and RYGB), achieving excellent symptom resolution and weight loss. Although this represents a single case, this outcome is encouraging and aligns with reports advocating for simultaneous surgical management in selected patients. Kaufman et al. [29] were among the first to demonstrate the feasibility and efficacy of this combined procedure, noting the added advantage of RYGB in minimizing postoperative reflux. In their report, the patient had excellent relief of dysphagia, no heartburn, and a weight loss of 100-lbs one year postoperatively. Wesp et al. [30] advocate for concurrent HM and RYGB as the preferred strategy due to its dual benefit of symptom control and weight loss. Heller myotomy appears to be the optimal procedure to combine with RYGB, as it offers superior control of postoperative reflux compared to partial fundoplication. In patients with severe obesity and achalasia who are suitable candidates for simultaneous treatment, HM and RYGB can be performed safely. This combined approach streamlines care, reduces the need for reoperation, and limits cumulative anesthesia exposure, all while providing durable long-term outcomes [31]. Nevertheless, it requires thorough multidisciplinary planning to effectively balance operative risks and procedural complexity.

This study is limited by its retrospective design, small sample size, and incomplete manometric or follow-up data in some cases. Heterogeneity in achalasia subtypes, treatments, and postoperative courses limits direct comparisons, and institutional practice patterns evolved over the study period; in addition, the retrospective design and outside referrals with incomplete prior records contributed to variability in treatment selection, particularly in earlier cases. This study is further limited by the absence of standardized symptom scores such as the Eckardt score; symptom outcomes were instead based on clinical documentation rather than validated scales, introducing some subjectivity. In addition, quality-of-life outcomes following these treatments were not captured. Despite these constraints, our findings add to the limited literature on esophageal motility disorders in the bariatric population and emphasize the need for larger, multicenter studies to inform evidence-based treatment algorithms. A key strength is the relatively long follow-up and stratification by treatment sequence, allowing for a more nuanced analysis of outcomes, including symptom control, weight loss, and complications. These results underscore the importance of standardized protocols and future research to guide surgical decision-making in this complex group.