Brief Answer:
it could be related
Detailed Answer:
Hello, i will try to answer your question as best as i can with the little information provided.
An
alkaline phosphatase of 479 is quite high. Depending on the lab, the upper limit of normal is usually around 125 - 140. The alkaline phosphatase can go up, and it could be related to many organs. The organs that can produce this enzymes are: liver, bone, intestine (and placenta, which does not apply to your son obviously).
Usually this enzyme is only used in adults, as it can be abnormal in kids due to growth spurts (due to the bone release), and therefore can be as high as 500 during growth spurts. So this could be happening to your son (if the rest of "liver tests" are normal).
The stomach pains are likely unrelated to the liver tests.
Bentyl can help with IBS or intestinal spasms, however keep in mind that a common side effect of this medication is somnolence and
dizziness.
Before diagnosing IBS some of the tests that are usually done are:
thyroid tests (decreased thyroid function can cause
fatigue and IBS type symptoms),
celiac disease blood tests, endoscopies. He can also be checked for an entity called "SIBO" (small intestinal bacterial overgrowth), which can cause "IBS type" symptoms, but most commonly
bloating.
Hope this helped, let me know if you have any further questions or concerns.