wie viel ballaststoffe haben bananen — when to see a doctor?

Bananas contain about 2–3 g of fiber per 100 g (depending on ripeness: unripe bananas have more resistant starch, ripe ones more soluble fiber). That's moderate – a medium banana (≈120 g) provides roughly 3 g of fiber. You should see a doctor if you experience persistent digestive issues (constipation, diarrhea, bloating) despite a fiber-rich diet, or if you have known fructose malabsorption / IBS – bananas can trigger symptoms in some individuals. Also seek medical advice for unexplained abdominal pain, blood in stool, or sudden food intolerance. The provided context does not contain specific information about bananas or fiber; this answer is based on general nutritional knowledge. Evidence: practice.