JOAN LLORET answers:
Our stomach growls mainly because the intestines are an empty, non-rigid viscera (like a pipe) approximately ten metres long that occupies much of the abdominal region. Furthermore, many liquids and solids from the food we eat pass through this pipe every day, generating movement and the formation of gases.
Despite being normal, we need to monitor an excessive loudness (with extreme flatulence due to various intestinal problems) or even the decrease or absence of abdominal noises, which could indicate a serious problem in this empty pipe.
This is why it is important not to overeat food items such as legumes and vegetables (cauliflower, cucumber, lentils, or onions), fruits such as pears or plums, dairy products such as milk or cheese, and also products like bread or cereals, with whole grains such as wheat or rye. We should also monitor liquids with a lot of gas.
Joan Lloret is a pediatrician and scientific collaborator at the Institute for the History of Medicine and Science of the University of Valencia.