This
theory
involving
chronic
venous
obstruction
suggests
that
____________________
episodes
of
colonic
distention
are
associated
with
____________________
increases
in
lumen
pressure
and
size
.
,
which
results
in
multiple
episodes
of
increasing
wall
tension
with
obstruction
of
submucosal
venous
____________________
,
especially
where
these
vessels
pierce
the
smooth
muscle
layers
of
the
colon
.
Over
many
years
,
this
process
____________________
gradual
dilation
of
the
submucosal
veins
and
,
eventually
,
dilation
____________________
the
venules
and
arteriolar
capillary
units
feeding
them
.
Ultimately
,
the
capillary
____________________
dilate
,
the
precapillary
sphincters
lose
their
competency
,
and
a
small
arteriovenous
communication
forms
.
____________________
accounts
for
the
characteristic
early
-
filling
vein
observed
during
mesenteric
angiography
.
