Untreated Congenital Hypothyroidism Mimicking Hirschsprung Disease: A Puzzling Case in a One-Year-Old Child

Figure 3

Anorectal manometry (ARM, balloon method) before treatment (a) and six months after adequate treatment with levothyroxine sodium (LT₄) (b). ARM was used to measure contractility in the anus and rectum. This technique used a balloon to distend the rectum and a pressure sensor at the internal anal sphincter to measure the presence or absence of the rectosphincteric reflex. (a) ARM showed great variation in the internal anal sphincter resting pressure (in mmHg). Red circles represent transient internal anal sphincter relaxations that occurred independent of the balloon distension pressure (rectal stimulus). This ARM was considered to be inconclusive. (b) ARM six months after replacement therapy with LT_4. The internal anal sphincter resting pressure was normal, without variations. There was no decrease on internal anal sphincter resting pressure without rectal stimulus. Rectoanal inhibitory reflex was present with 15, 20, 25, and 30 mL of air insufflated in the rectal balloon. This ARM was considered to be normal.

(a)

(b)