Abdominal pain when running

Question
I'm 32 years old and consider myself not much more than a beginner in running.  I had built up to 2miles running a couple of years ago but then i had to stop because i needed abdominal surgery and obviously needed recovery time.  I'm now 18 months after the surgery & my doctor cleared me to exercise again a long time ago however it took me ages to get round to it again. I'm in good general health, 5ft4, 123pounds. Now i've been going to the gym again for 3 months, 2 or 3 times a week,  just building up general fitness & i'm now starting to train to do a leg of a marathon in may (prob only 4miles).  Problem is now after running for only about 10 mins i'm getting muscle pains in the middle of my abdominal area, probably about the same level as a stitch would be but in the middle not on the side.  (sometimes i get a stitch on the right side as well but i've realised that's probably because i've been drinking too much water just before & during my run.)  This is really frustrating because i have to at least slow to a walk for a few mins to get rid of it & even then it sometimes returns maybe 5mins later.  Once i had to stop altogther, even walking was too sore, although the pain completely went within a couple of mins.  Is this likely to be a result of weak abdominal muscles? Should i be doing sit-ups or some sort of exercises on that area?
I really want to be able to do this relay marathon in  may, it's for a really good cause!

Answer
I think May is a very reasonable goal.
It's hard for me to say whether it is a normal weakness pain, a pulled muscle or tendon pain, or a cut up muscle pain. It's hard for me to just be thinking about trying to run after your muscle has been cut open like that.
I don't think your abdominal muscle is weak or out of shape, but hurt somehow. If you can't recover by jogging with adequate rest and recovery time, you may have to just stick it out and keep running. Is it so bad that you can't keep running during a workout? If so, you might just see a doctor. Sorry it took so long to reply, and sorry I can't help much.
Jared