Achalasia is a rare disorder which makes it hard for food and fluid to pass in your gut. Achalasia happens when nerves at the tube linking your mouth and stomach (esophagus) eventually become damaged. Because of this, the esophagus gets the capability to squeeze down food, along with the muscular valve between the esophagus and stomach (lower esophageal sphincter) does not fully relax -- which makes it difficult for food to pass in your gut.



There is no treatment for achalasia. But symptoms can usually be handled with minimally invasive treatment or surgery.

Diagnosis
Achalasia can be overlooked or misdiagnosed because it has symptoms similar to other digestive disorders. To test for achalasia, your doctor is likely to recommend:

Esophageal manometry. This evaluation measures the rhythmic muscle contractions into your stomach when you consume the coordination and push exerted by the stomach muscles, and also how well your lower esophageal sphincter relaxes or opens during a swallow.
Upper endoscopy. Your doctor inserts a thin, flexible tube equipped with a light and camera (endoscope) down your throat, to examine the inside of your esophagus and stomach. Endoscopy can be used to define a partial blockage of the esophagus if your symptoms or results of a barium study indicate that possibility. Endoscopy can also be used to collect a sample of tissue (biopsy) to be tested for complications of reflux such as Barrett's esophagus.
X-rays of your upper digestive system. X-rays are taken after you drink a chalky liquid that coats and fills the interior lining of your digestive tract. The coat allows your physician to find a shape of your stomach, stomach,  and upper intestine. You can also be asked to swallow a barium pill which could help demonstrate a blockage of the esophagus.
Achalasia Treatment
Achalasia treatment focuses on relaxing or forcing open the lower esophageal sphincter so that food and liquid can move more easily through your digestive tract.

Specific treatment depends on your age and the severity of the condition.

Nonsurgical treatment
Nonsurgical options include:

Pneumatic dilation. A balloon is inserted into the esophageal sphincter and inflated to expand the opening. This outpatient procedure might have to be replicated if the esophageal sphincter does not stay open. Nearly one-third of individuals treated with balloon dilation require repeat therapy within six years.
Medication. Your doctor might suggest muscle relaxants such as nitroglycerin (Nitrostat) or nifedipine (Procardia) before eating. These medications have limited treatment effect and severe side effects. Medications are generally considered only if you're not a candidate for pneumatic dilation or surgery, and Botox hasn't helped.

Source: https://aderonkebamidele.com/achalasia-causes-symptoms-treatment/