A tubular connector for use with a spiral tube used on an insertion section of an endoscope. The tubular connector including: an outer surface; an inner surface; and a plurality of cams circumferentially spaced on the inner surface to project radially inward from the inner surface, the plurality of cams extending in a longitudinal direction of the tubular connector; wherein each of the plurality of cams have one or more cam surfaces configured to engage a rotating member to rotate the spiral tube. The plurality of cams can alternatively be formed directly on an interior surface of the spiral tube.