I cruise through 48hrs with zero symptoms. Usually they don’t kick in until around day 5. I think it comes down to fasting experience be it dry or not.
I did regularly extended fasting(7-21 days) for years and also Alternate Day Fasting as a normal schedule where you fast every other day 36-48hrs.
Fasting is a skillset. The more you do it the easier it gets. But also the quality of your overall diet affects your fasting experience.
If you eat high a combination of high fat, sugar and salt diet (basically most processed foods) you’re going to have an unpleasant fast.
If you are having symptoms then ideally schedule your fasts on your days off