All lanes have re-opened on the M4 after traffic was briefly held. 

Traffic was held on the M4 eastbound just before 3pm between J18 A46 (Bath / Tormarton) and J17 A350 (Chippenham) to clear debris off the motorway from an accident.

Stroud News and Journal:

(Traffic was held on the M4)

The accident happened on the westbound side of the road, but the debris flew across the carriageway onto the eastbound side of the road.

All lanes re-opened shortly after 3pm.

Traffic is easing.