You Do Need power plug adapter while traveling from Bahrain to Bangladesh.

Here is Why You Need An Adapter

The outlet and plug type used in Bangladesh are A, C, D, G and K and in Bahrain is G. This is how they look like.

Bahrain

In Bahrain, outlets of type G are in use.

Type G

Bangladesh

In Bangladesh, outlets of type A, C, D, G and K are in use.

Type A

Type C

Type D

Type G

Type K