A medical device for suturing tissue, the medical device comprising: an endcap having - a tubular body defining an interior space and a longitudinal axis, - a first arm projecting from the tubular body to a first free end, and - second arm projecting from the tubular body to a second free end, wherein the first and second arms are spaced laterally apart on opposite sides of the longitudinal axis; the first arm defining a first passageway having a first port at the first free end, the second arm defining a second passageway having a second port at the second free end, the first and second ports spaced apart a fixed distance (d, D); a needle having first and second ends shaped to pierce tissue, the needle sized to be slidably received within the first and second passageways of the first and second arms, the needle extending over a length (l, L) between the first and second ends, the length (l, L) of the needle being greater than the fixed distance (d, D) between the first and second ports; a suture attached to the needle between the first and second ends of the needle; a first control member slidably received within the first passageway of the first arm and positioned to engage the first end of the needle, distal movement of the first control member moving the needle distally through the first passageway; and a second control member slidably received within the second passageway of the second arm and positioned to engage the second end of the needle, distal movement of the second control member moving the needle distally through the second passageway; characterized in that the medical device further comprises an endoscope having a distal end to which the endcap is connected; and the first and second control members are elongated and run alongside the endoscope. an endcap having - a tubular body defining an interior space and a longitudinal axis, - a first arm projecting from the tubular body to a first free end, and - second arm projecting from the tubular body to a second free end, wherein the first and second arms are spaced laterally apart on opposite sides of the longitudinal axis; - a tubular body defining an interior space and a longitudinal axis, - a first arm projecting from the tubular body to a first free end, and - second arm projecting from the tubular body to a second free end, wherein the first and second arms are spaced laterally apart on opposite sides of the longitudinal axis; the first arm defining a first passageway having a first port at the first free end, the second arm defining a second passageway having a second port at the second free end, the first and second ports spaced apart a fixed distance (d, D); a needle having first and second ends shaped to pierce tissue, the needle sized to be slidably received within the first and second passageways of the first and second arms, the needle extending over a length (l, L) between the first and second ends, the length (l, L) of the needle being greater than the fixed distance (d, D) between the first and second ports; a suture attached to the needle between the first and second ends of the needle; a first control member slidably received within the first passageway of the first arm and positioned to engage the first end of the needle, distal movement of the first control member moving the needle distally through the first passageway; and a second control member slidably received within the second passageway of the second arm and positioned to engage the second end of the needle, distal movement of the second control member moving the needle distally through the second passageway; characterized in that the medical device further comprises an endoscope having a distal end to which the endcap is connected; and the first and second control members are elongated and run alongside the endoscope.