Hi.
The pain on right side of the abdomen from belly button to hip which comes and goes, increasing with walking, running , bending is suggestive of an inflammatory process on the right side.
The probable causes are :
appendicitis , Meckel's
diverticulitis, and so on.
I would suggest you the following:
Blood- complete blood picture, kidney functions tests, blood sugar fasting and post-lunch,
Urine- routine,microscopy, culture and sensitivity ( before start of antibiotic)
Ultrasonography of abdomen.
To confirm the findings by CT scan of the abdomen.
If surgical cause is found go for surgery.
If no surgical cause is found, take a course of an antibiotic,
metronidazole, and supportive medicines as prescribed by a
General Surgeon.