Mom ,age 55 had covid in dec .post that since Jan till date, severe burping,acid coming up to chest and head ,along with frequent motions .IBS syndrome Endoscopy and stool test is normal, Thyroid test is also normal Also feeling chills at times . She takes Temsi AM for Bp and is thalassemia minor She was taking ayurvedic medicine and motions is little better Please advise the right treatment / remedy that she should take  as at this times your help will go a long way in prayers .Also please suggest something for immunity and supplements as she is not taking anything due to lot of acidity