Remove your oil filter and very carefully, cut it open, taking care not to contaminate it with too much iron filings. Remove the paper element and open it up. You are looking for silvery flakes, and if your bearings have disintegrated, the filter will be full of them. This is white metal, the material that big end bearings are made of.
If you find this metal in the filter, then you are in for an engine rebuild or change. This metal is not attracted by a magnet.