It about your diet that makes your asshole burn and grows hemorrhoids. When you poop they break and you bleed. Eat more vegetables, fish and proteins. Less sugar and carbohydrates, no fastfood, drink only water.
Doctors do the same and even asking moneys for that. Or do you think that your doctor gladly will take a look at your asshole without hesitation? It's all about careless hipotesis till you die on pain or you are ready to burn cash.
I have no idea where you get the idea that doctors do diagnosis without examination. I work in the medical field and have contact with many doctors, and no one is as careless as you suggest. Quite the contrary, actually.