Risks of chronic, very low dose and intermittent use of Ibuprofen?

Hi,
I suffer from a chronic pain condition in one hip joint (curratage of tumor inside femoral head) .
The pain, I believe, is similar to that caused by avascular necrosis or a stress fracture.

I have found that Ibuprofen is very effective to reduce this pain - sometimes 200mg makes all the difference in the world.(I belive that it's a microscopic inflammation that's pressing on a nerve or something).
Often the effect remains even after the effective period of Ibuprofen (4-6h), meaning that the drug can help stopping a vicious circle of pain.


So, my question is what the risks of chronically taking 0-800mg daily would be?
(Most days would be 0 mg.)
Also, how long period of rest from Ibuprofen do the GI-tract need to fully recover from the "bombardment".

Example usage pattern (mg/day, repeated forever)
0,0,0,0,0,200,200,400,400,0,0,0,0,0,0,200,200,0,0,0,0,0,0,0,0,0,800,800,400,0,0,0,200,0,0

[Burton Dunaway, PharmD]

The risk for a young person with no history of gastrointestinal (GI) problems is low, but GI side effects are still possible.  Ibuprofen irritates the lining of the stomach and inhibits the production of the mucus that protects the stomach. Many people can take ibuprofen daily with no gastrointestinal (GI) problems, but about one-fourth of patients will develop GI side effects. Patients with a higher risk of having a gastrointestinal problem include those with a history of stomach ulcers or acid reflux (heartburn), cardiovascular disease, age over 60, and male gender. Taking ibuprofen only periodically and with food can help minimize GI problems. Stop taking ibuprofen and call your physician if you notice black or bloody stool, acid reflux, nausea, or chest pain.