My daughter took omnacortil 40 on dr's advice just one month back & now she is having an acute stomach pain in just above her navel area. she is 17yr ?

Likely NOT related: Omnacortil is branded steroid called prednisolone, a commonly used medication which has powerful antiinflammatory effect. Typically it used for a short period of time, 3-7 days range. It has a relatively short half-life and thus out of the system quite quickly after last dose. As a result, i would not pin this med as cause of her abd pain. Get her evaluated as soon as feasible. Good luck.