<s>
The	O
per-oral	B-Algorithm
endoscopic	I-Algorithm
myotomy	I-Algorithm
,	O
or	O
POEM	O
,	O
is	O
a	O
minimally	O
invasive	O
surgical	O
procedure	O
for	O
the	O
treatment	O
of	O
achalasia	O
wherein	O
the	O
inner	O
circular	O
muscle	O
layer	O
of	O
the	O
lower	O
esophageal	O
sphincter	O
is	O
divided	O
through	O
a	O
submucosal	O
tunnel	O
.	O
</s>
<s>
POEM	O
is	O
a	O
form	O
of	O
natural	B-Algorithm
orifice	I-Algorithm
translumenal	I-Algorithm
endoscopic	I-Algorithm
surgery	I-Algorithm
,	O
or	O
NOTES	O
.	O
</s>
