hello thank you for trusting HCM dear nothing to worry, stomach discomfort may be due to gastritis,or irritable bowel or celiac disease or malobsorption or dysentery etc. malignancy common in old age with smoking and alcohol history,also may present with weight loss with generalised weakness. avoid spicy food and alcohol and regular exercise. next time give your history properly (about diet,other symptoms, stools etc..). if symptoms not improved please consult your doctor he will examine and treat you accordingly. I think I answered to your question if you have more questions feel free to ask. take care