Sharp pain in lower right side of abdomen when holding a deep breath especially if sitting mildly slouched, gp said ibs due to bloating. not appendix?

Unlikely: How are your bowels? Look for fever and nausea for appendicitis. For gas bubble (relative constipation) look to see if your diet is full of fiber and minerals, exercise daily and drink water. A localised leaking cyst on your ovary (happens every month) can make this a passing problem.. Always see your doctor for a proper exam, if not better after a few days.