The views expressed by me are for educational purposes only and do not establish a doctor patient relationship.
Thanks for your question.
Esophageal spasm and also acid reflux can cause persistent cough.
Since you had extensive work up, any underlying serious cause is unlikely.
The coughing is likely due to the irritation of the airways from acid and also from the excess response from the cough reflex.
Hence, you should be on a PPI like nexium daily.
Also, surgical repair of the hiatal hernia may be considered if medications failed.
The surgery may stop acid reflux better.
Nissen fundoplication is the common procedure.
Hence, you can see a GI surgeon for that.
In resistant cough symptoms, low dose narcotic medication may be used although this is not the best option with history of sleep apnea.
Codeine or morphine can be used as needed basis.
Oral steroid inhaler is another option if not tried.
Then surgery is the only option left for you realistically.
The most common surgical treatment is the laparoscopic Nissen fundoplication. This procedure involves wrapping the upper part of the stomach around the lower end of the esophagus .
Also watch your diet.
Your diet should contain moderate amount of dietary fibers.
Initially you should cook your vegetables well to make the fibers soluble for easy digestion.
Avoid meat, fish, chicken, eggs.
No animal products.
You can have plant proteins, like tofu, tempeh, lentils, rice etc.
Avoid nuts, seeds, beans, cabbage, broccoli, cauliflower.
Also avoid sweets, cake, dessert, ice cream, caffeine as they worsen acid reflux and bloating symptoms.
Add Dill weed powder and caraway seeds to your food every time.
Try aloe vera 1/4 cup + pomegranate juice 1/2 cup every morning-- helps digestion.
Also try Dandelion tea 1-2 cups daily, white bean hummus.
Also take 2 cloves of garlic daily, wormwood tea 1 cup daily, papaya seed and honey mixture daily.
Also consider taking a probiotic daily.
Phillip's Colon Health is a good probiotic and helps in improving colon health.
Also take activated charcoal supplements daily and drink 1 cup of peppermint tea in the morning and evening daily to prevent acid reflux.
Aloe vera juice, chewing gum daily will prevent acid reflux as well.
please see my reply above.