PAST MEDICAL HISTORY:  Rectal fissure 10 months ago.
 The patient suffers from constipation. 
(ROOT (NP (NP (NP (JJ PAST) (JJ MEDICAL) (NN HISTORY)) (: :) (NP (NP (JJ Rectal) (NN fissure)) (ADVP (NP (CD 10) (NNS months)) (RB ago)))) (. .)))
(ROOT (S (NP (DT The) (NN patient)) (VP (VBZ suffers) (PP (IN from) (NP (NN constipation)))) (. .)))
( ( ( ( PAST ( MEDICAL HISTORY ) ) : ) ( ( Rectal fissure ) ( ( 10 months ) ago ) ) ) . )
( ( The patient ) ( ( suffers ( from constipation ) ) . ) )