Nausea and stomach pain in a child are usually due to mild stomach upset, food intolerance, or eating habits that irritate the stomach. Try offering smaller, lighter meals at regular times, and avoid heavy, oily, or very spicy foods so the stomach is not strained. Encourage the child to eat slowly and chew properly for better digestion. Keep the child well hydrated with water and give simple foods like rice, banana, or toast to help settle the stomach, and let them sit upright after meals instead of lying down. Notice whether certain foods trigger the problem or if symptoms such as vomiting, fever, or weight loss appear. Consult a doctor who can assess the cause and guide you on proper care.