In this study, we will evaluate the incidence of reflux esophagitis between two different techniques of posterior per-oral endoscopic myotomy (POEM) i.e. conventional POEM versus oblique/ sling fiber sparing POEM. This is a randomized trial where the patients with idiopathic achalasia will be randomized in two groups in 1:1 fashion into groups.

In this randomized trial, patients with idiopathic achalasia will undergo POEM using two techniques as follows. In the first technique, a conventional posterior POEM will be performed where the sling or oblique fibers will not be spared during POEM. Sling or oblique fibers will be recognized using the configuration of fibers below the gastroesophaeal junction and by identifying the border between the sling fibers and the circular fibers which is formed by the penetrating vessels. In the second group (Oblique fiber group), the sling fibers will be selectively spared and only the circular fibers will be spared.

The other steps of the POEM procedure will be the same as described in the standard technique of POEM. These include submucosal injection of saline mixed with indigo carmine dye, mucosal incision, submucosal tunneling using triangular knife in spray coagulation mode (Effect 2, Watts 50), myotomy extending upto 2-4 cm below the gastroesophageal junction and the closure of mucosal incision using endoclips.

Post POEM management: All the patients will be kept nil per oral for about 24-hours after the procedure. A timed barium swallow will be performed the next day and oral liquids will be started. A soft puried diet will be started from day 3 onwards.

Oral proton pump inhibitors (PPIs) equivalent to 40 mg of Pantoprazole per day will be prescribed to all the patients unless a contraindication exists.

Follow-up: The first evaluation will be performed at 2-months after POEM. During this evaluation, the following parameters will be recorded: symptom relief, reflux symptoms, and esophageal acid exposure. PPIs will be stopped for 1-2 weeks prior to the evaluation of GERD.

Subsequent evaluation will be at 6-months for reflux symptoms and symptoms of achalasia using Eckardt scores.

Inclusion Criteria:

1. Patients with type 1 and 2 achalasia with Eckardt score >3 (0-12 scale achalasia).
2. Patients with age 18-75 years.
3. Patients who are treatment naïve or have a history of pneumatic balloon dilatation.
4. Patients who are willing and able to comply with the study procedures and provide written informed consent form to participate in the study

Exclusion Criteria:

1. Patients with type 3 achalasia cardia or any other esophageal motility disorder,
2. Patients who have undergone previous surgery of the esophagus or stomach,
3. Patients with active severe esophagitis,
4. Patients with large lower esophageal diverticula,
5. Patients with large ( > 3cm ) hiatal hernia,
6. Patients with sigmoid oesophagus,