The pyloric obesity valve includes a tubular valve body having proximal
and distal ends. The valve body has an intermediate section which is
between the proximal and distal ends. The proximal end is enlarged
transversely relative to the intermediate section. The valve body has an
inner surface and a lumen. The inner surface which is within the
intermediate section has a cross-sectional area which is smaller than a
cross-sectional area of the inner surface which coincides with the
proximal end to resist a flow through the lumen of the valve body from
the proximal end to the intermediate section.