Some people can't get enough spicy food and can happily eat the hottest curries whenever they like. However, others find that spicy foods cause heartburn, stomach pain and even diarrhoea. Sometimes even milder foods like garlic or onion can cause these symptoms too. If spicy foods do have this effect on you, it goes without saying that it's best to go easy on them or choose a milder option in future. If you already experience heartburn or have irritable bowel syndrome, it's probably best to avoid them completely.