A NSV of Sorts - No Stomach Cramps when I exercise?

I started exercising in earnest about 3 months ago, shortly after joining on here. I upped my time on the treadmill until I felt confident enough to go and run outside. I hadn't been out running for years. The first time was horrendous, as I hit the wall after about 30 mins and had to walk home, but this week I have run the equivalent of 4 half marathons!

But the NSV I wanted to post is that when I first started exercising, I used to get horrible stomach cramps afterwards (the run to the toilet sort of cramps). I used to deep breathe my way through them, as they never materialised into anything, but they were pretty uncomfortable and unpleasant.

But now I never get them, touch wood. I've no idea why you get them in the first place, but I'm pretty sure that the reason I'm not getting them now is because I'm so much fitter. Anyone else experience this?