Yeah, when I was a kid I did get it like 5-6 days a week, almost every time we played football in the yard. It was like a mild charlie horse on my side below the floating rib.
This is interesting because it is more cardio/endurance related. If your workout isn't crossfit-like, it may be an indication of some internal trouble. If you're not doing cardio now, start. Does it happen then too?
Here's what I found:
What Is a Side Stitch? - Abdominal Pain - HealthCommunities.com
If you fix it great! However, if it is ongoing or a sign of something else, please update this thread. TY