following a C section may be due to adhesions of the internal structures.
But pain of burning nature of the upper abdomen may be due to Gastritis(Inflammation of the stomach).
In this situation I would advice my patients to
Avoid spicy food, tea, coffee and carbonated beverages.
Eat frequent small meal for easy digestion.
Take proton pump
If the symptoms still persist then consult a Gastroenterologist
he may advise you Ultrasound
abdomen and Upper GI endoscopy which may help in diagnosing the problem.