You Do Need power plug adapter while traveling from Belgium to Laos.

Here is Why You Need An Adapter

The outlet and plug type used in Laos are A, B, C, E and F and in Belgium are C and E. This is how they look like.

Belgium

In Belgium, outlets of type C and E are in use.

Type C

Type E

Laos

In Laos, outlets of type A, B, C, E and F are in use.

Type A

Type B

Type C

Type E

Type F