A fluid flow control device, particularly useful for drip-irrigation emitters, for controlling the discharge of a fluid (water) from a discharge port in a fluid conduit (drip irrigation pipe) includes: a housing attachable to the fluid conduit and constructed to define a fluid chamber having an inlet opening communicating with the interior of the fluid conduit, and an outlet opening communicating with the discharge port of the fluid conduit; and a flow control member freely movable within the fluid chamber and having a surface contacting an inner surface of the housing to control the flow of fluid from said fluid chamber out of the fluid conduit via said outlet opening in the housing. One of the contacting surfaces of the flow control member or housing is formed with a protruding pattern such that the two contacting surfaces define small passageways for the flow of fluid from the fluid chamber out of the fluid conduit via the outlet opening. The flow control member is manually accessible, via the outlet opening, to be manually moved away from the outlet opening in the fluid chamber and thereby to flush the small passageways of any clogging particles.