I'm going to echo what someone else said above: If you get the runs from Taco Bell or gas station food, that's just natural selection at work. A healthy immune system and digestive system should be able to cope with anything that doesn't cause an actual in-the-news health scare. Sorry, you just got a poor roll of the dice when the divinities were rolling up your character.
I don't know if it's my tastebuds or if it's the sauce they always have in stock at the one near me, but Diablo sauce tastes like literal nothingness to me. No flavor. No heat. Nothing. Just.. sauce. Fire sauce, hot sauce, even fucking mild all have flavor and at least tiny bit of heat, but Diablo is just emptiness in a packet.
It tastes sweet and sugary to me. Not actually that hot, though. Hmm.
To me, the Diablo sauce has a citrus-y flavor. It's not sweet, but it is a bit tangy. And it's warm enough for me that I can stretch one packet over two tacos and still get them enjoyably warm.I like the spicy flavor it has. Fire sauce tastes to sweet to me.