This answer is not to worry you; but rather a worst case scenario...
My daughter had stomach pains, followed by constipation in mid-december. We took her to the ER (didn't know about the constipation yet), thinking it was her appendix. They told her it was a UTI and bad constipation. She took antibiotics for the UTI and had all the "usual" for bad constipation.
Weeks passed. Fevers came and went. "Atypical" chickenpox reared it's ugly head (not bad at all - but the dr. thought it was the explanation for the fever). Constipation persisted? She was still having pain on the toilet, but we figured she was so constipated, the "new" poop was passing by the old, and slowly "chipping" away at it...
I kept taking her to the dr. Pain on the toilet was unbearable - I knew that something was wrong, but couldn't figure out what it was.
Finally, her dr. did a ctscan. It showed an abscess 5cm big in her abdomen. This was January 7th.
We went to the hospital that night - did another ctscan and it showed a blood clot (due to the abscess), and a fistula (a little tube that is a trademark of Chron's) that had formed from the intestine to the abscess. They said it was Chron's Disease and moved us up to the GI floor...
**MANY tests and meds omitted for the sake of time**
On the GI floor, they said it was Chrons, but to have proof, they needed to do a colonoscopy (and the one down the throat - I forget what that one is called.) She had one of the top GI drs in the nation working with her.
We did this prayer... a healing prayer... every night in the hospital. (More on this later.)
My daughter even was having bloody stools. I mean bloody! Then, the colonoscopy day came... She had the procedure done, the doctors called us in the consultation room. My heart was in my toes. The doctor was stunned. He said her colon (and all) was perfectly healthy. He couldn't explain it. They took 14 biopsies to try to find what caused all of this.
She was sent home. No more symptoms. We then waited for the biopsy results. Days later, the results came back normal. Nothing wrong. No Chron's. No digestive disease - much to the surprise of the doctor who specializes in digestive diseases.
So, now, she is enduring 2 shots in the belly daily for a blood clot that they could no longer see on another ctscan (after we started the prayer). She will be off the shots soon.
All of this because of constipation. She was in the hospital for 2 weeks. We did the prayer over and over at night. If anybody wants the prayer - let me know and I will send it to you. It is not religion specific.
I guess what I am saying is to please take your son to the doctor! It is better to be safe than have to go through all of this!