Achalasia is a neuro-degenerative disorder marked by changes in the peristalsis of the esophagus and the lack of relaxation in the lower esophageal sphincter (LES), thought to be due to damage to the myenteric plexus with an unknown cause.1 Per-oral endoscopic myotomy (POEM) is an established endoscopic treatment modality for achalasia. Leading gastrointestinal (GI) societies endorse POEM as one of the primary treatment option for achalasia.This study aims to characterize and compare the morphological characteristics of reflux related erosions after the POEM procedures versus those in cases without esophageal motility disorders.

Data collection

1. Demographic characteristics: Age, gender, type of achalasia
2. Manometry findings (pre and post POEM): integrated relaxation pressure, lower esophageal sphincter pressure
3. Comorbidities
4. Medications
5. Eckardt score: before procedure and 3-months after Procedure
6. POEM procedure details: length of esophageal and gastric myotomy, adverse events, length of hospital stay
7. Evaluation at 3-months Symptom: standardized questionnaire (GERDQ) Endoscopy: grade of esophagitis Erosions vs ulcers Dimension of erosions Anatomical location (according to clock)

POEM will be performed using a standardized technique.8 The patients will be prescribed a single dose anti-secretory medicine (equivalent to 40 mg esomeprazole) for two months after POEM. Consecutive patients who meet the inclusion and exclusion criteria will be followed up after 3 months. PPIs will be discontinued for at least 4 weeks prior to objective evaluation of GERD. Each patient returning after 3 months for follow up will undergo several follow up examinations, including GERD questionnaire scoring, Esophagogastroduodenoscopy, 24 hour pH impedance test. Presence of endoscopically visible esophagitis . Endoscopic findings such as anatomical location, dimensions of the mucosal breaks will be compared to general population with diagnosis of GERD who have endoscopically visible esophagitis.

Inclusion Criteria:

1. Age≥18y,
2. confirmed diagnosis of Achalasia,
3. No contraindication to POEM,
4. erosive esophagitis on endoscopy

Exclusion Criteria:

1. Non-esophageal esophageal motility disorders,
2. Treatment other than POEM,
3. current PPI use before assessment for GERD