Hi Sonali thanks for question.
You have not mentioned one of the most important point in history that is age of your mother.
your unable to differentiate between the stomach problems and heart problems of your mother.From the history of pain in heart ,both arms and shoulder after taking food,this is typically the pain of gastric ulcer.what your calling as pain in heart is retrosternal pain
which occur in gastric ulcer and reflux disorder.Difficulty in breathing and pain after exertion could be due to heart problems like ischemic heart Disease
.Your advised to get your mother consultation from a physician specialist ,who will work up her completely in the form of upper G,I endoscopy
, for stomach problems and ECG and echocardiography
for heart ailment and will also evaluate her for constipation
.Hope i answered your question.Regards