Hello!
According to your friends surgery history there is a probability of post-surgery adhesions. Especially she have had two of it. Adhesions may cause partial intestines obstruction (called subileus) which can reveal with intermittent
abdominal pain. If your friend has also constipations, diarrheas or both associated with abdominal pain and flatulences,
nausea and this symptoms may come and go, subileus is very probable.
Lower right abdominal pain is also characteristic for
appendicitis (what has to be always ruled out!), right
urinary tract infections/stones.
Backbone diseases can also show up with symptoms mentioned by you but (backbone
MRI may be required if all abdominal diseases are ruled out).
To rule out intestines obstruction abdomen X-ray is necessary (abdomen CT might not visualize it).
Blood tests needs to be repeated as white blood count and CRP may elevate after few days of disease appearance. This tests may be negative on the beginning of pathologic process. Urine tests should be done as well.
Take care