Yes. I believe stomach flu can last longer and become more severe with IBD.
I once got food poisoning in Costa Rica. I shared a meal with a friend and his food poisoning was not bad at all. A day at worst.
Mine was five days and was very severe. That's just one example of how a flu or stomach poisoning can exacerbate your underlying condition and wreak havoc on your body.
Best,
Matt (Team Member)