A suction control unit configured to be detachably attached to at least two working channels of an endoscope and control application of suction through at least one of the two working channels, the suction unit comprising: a housing, defined by a central longitudinal axis, comprising: a first valve and a second valve positioned on either side of the central longitudinal axis, wherein a proximal end of the first and the second valve has respective first and second valve openings that lead through to a distal end of the first and the second valve, and wherein the distal end of the first and the second valve is configured to be detachably attached to first and second ports of the two working channels; a channel extending between the first and the second valve within the housing, wherein a channel axis is substantially perpendicular to the central longitudinal axis of the housing; an opening extending from a front wall to a rear wall of the housing and through the channel between the first and the second valve; and a switcher having a handle and a shaft extending from the handle along a long axis, wherein the shaft has a through hole such that a hole axis is substantially perpendicular to the long axis, wherein, when the shaft is placed within the opening and turned to a first position, the hole axis aligns with the channel and thereby opens the channel, enabling suction to be applied to both of the two working channels, and wherein, when the shaft is placed within the opening and turned to a second position, the shaft blocks the channel and enables suction to be applied to only one of the two working channels. a housing, defined by a central longitudinal axis, comprising: a first valve and a second valve positioned on either side of the central longitudinal axis, wherein a proximal end of the first and the second valve has respective first and second valve openings that lead through to a distal end of the first and the second valve, and wherein the distal end of the first and the second valve is configured to be detachably attached to first and second ports of the two working channels; a channel extending between the first and the second valve within the housing, wherein a channel axis is substantially perpendicular to the central longitudinal axis of the housing; an opening extending from a front wall to a rear wall of the housing and through the channel between the first and the second valve; and a first valve and a second valve positioned on either side of the central longitudinal axis, wherein a proximal end of the first and the second valve has respective first and second valve openings that lead through to a distal end of the first and the second valve, and wherein the distal end of the first and the second valve is configured to be detachably attached to first and second ports of the two working channels; a channel extending between the first and the second valve within the housing, wherein a channel axis is substantially perpendicular to the central longitudinal axis of the housing; an opening extending from a front wall to a rear wall of the housing and through the channel between the first and the second valve; and a switcher having a handle and a shaft extending from the handle along a long axis, wherein the shaft has a through hole such that a hole axis is substantially perpendicular to the long axis, wherein, when the shaft is placed within the opening and turned to a first position, the hole axis aligns with the channel and thereby opens the channel, enabling suction to be applied to both of the two working channels, and wherein, when the shaft is placed within the opening and turned to a second position, the shaft blocks the channel and enables suction to be applied to only one of the two working channels.