Rivers re-route themselves frequently, the difference is cause (sediment for the Yellow River, melting glacier for the Slims).

The re-routing of rivers within their deltas, due to sediment deposition, is how deltas get to be delta-shaped. The thwarted (at least for now) capture of the Mississippi by the Atchafalaya, mentioned on another comment, would have been another example of this.

The Amazon is another example of having flow reversal - presumably things got very damp as water levels sorted themselves out.