Shower arm for shower wc

A shower arm (31) for a shower WC (30) or bidet comprising:

• a shower nozzle (4, 14b, 24) from which shower water can pass in the direction of and for cleaning a user of said shower WC (30);
• a water supply pipe (7, 17, 27) for supplying water to said nozzle (4, 14b, 24) and a swirl chamber (8, 18, 28) in said water supply pipe (7, 17, 27) for generating rotating water flows in shower water delivered to said nozzle (4, 14b, 24);
• and
• a water pipe portion (4, 14a, b, 24a) between said swirl chamber (8, 18, 28) and a nozzle outlet opening of said shower nozzle (4, 14b, 24), said water pipe portion having a cross-section being at the most as large as that of said water supply pipe (7, 17, 27) directly in front of said swirl chamber (8, 18, 28),
• wherein said swirl chamber is a spherical chamber (8, 18, 28) with an internal dimension greater than that of a section of said water supply pipe (7, 17, 27) directly preceding said spherical chamber (8, 18, 28) and is spherical in shape apart from an inlet opening and an outlet opening of said water supply pipe (7, 17, 27) and any edge cross-overs at these openings.