How can one best alleviate the pain of a fractured rib and how long should pain last?

Ouch!: Rib fractures can be extremely painful. We used to prescribe chest binders - a wrap that goes around your chest - to help support the area, but no longer do so because it's been found that they don't help healing or pain much. You can get some pain relief by taking anti-inflammatory medications (like ibuprofen). Be sure to not take more than recommended. Ice applied to the area might help too.

Time is the best: It depends on the full extent of the fracture(s) but the pain should be almost completely gone by 2-3 months. Time is the best healer or most simple fractures, while surgery is indicated for complex chest wall injuries.