Sometimes, when I have fasted for several hours, I get a sore stomach followed by general gastrointestinal pain and bloating accompanied by gas from both ends.
Case in point, yesterday I had a fasted blood test so I did not eat between 7pm and around 12pm the following day. I ate an apple, followed a short while later by some ground beef and salad.
Later in the afternoon/evening I had the above pain and gas.
My wife was the one who suggested the link between not eating for some hours and then eating and I think she is right that there is that correlation.
I felt fine before, during and immediately after eating. Hungry, but not ravenous. I did perhaps eat too fast as I had to get back to work.
Is it as simple as "don't eat too much, too fast" after when breaking the fast?
I naturally fast 24-36 hours frequently and do not have any issues with how much I eat to break the fast, I just eat normally, sometimes a lot sometimes not. I have found that apples to cause me some intestinal distress, but I can eat almost anything else. Not sure how long you have been doing the Paleo Lifestyle but perhaps your gut is still healing and perhaps can get a little sensitive, maybe try some bone broth to break a fast.
my daughter has the same problem. For years she has complained about pain in her stomach area, and i just barely after 20 years figured out the correlation between her getting this pain when she hasn't eaten for a long while and is very hungry then eats and afterwards has pain. I was hoping i would find the reason why on this site.