A 22-year-old African-American man with a history of frequent episodes of constipation since infancy presented with 5 days of constipation and abdominal pain. Physical examination was significant for a massively distended abdomen with diffuse tenderness to palpation and a firm mass throughout the abdomen.
Richard W. Skinner, DO, MBA
, a Transitional Intern at San Joaquin General Hospital, French
A 22-year-old African-American man with a history of frequent
episodes of constipation since infancy presented with 5 days of
constipation and abdominal pain. Physical examination was
significant for a massively distended abdomen with diffuse
tenderness to palpation and a firm mass throughout the abdomen.
Bowel sounds were present and normoactive. Initial laboratory data
revealed a mild leukocytosis with a white cell count of 11,100 per
µL and low serum potassium of 3.1 mmol/L. Other electrolytes and
liver function tests were within normal limits.
Attempts at treating this patient's obstipation medically with
rectal tube decompression, bowel rest, and enemas failed. He was
taken to surgery for subtotal colectomy with disimpaction and
colostomy. Postoperatively, the patient had a well-functioning
colostomy and became asymptomatic.
Hirschsprung's disease (colonic aganglionosis) with resulting
Plain film of the abdomen demonstrates massive distention of the
sigmoid colon and rectum with inspissated feces in a ground-glass
appearance (Figure 1). The sigmoid colon fills the entire pelvis
and much of the abdomen. The colon is dilated to the splenic
flexure, as seen on the chest film from the abdominal series
The patient underwent subtotal colectomy for the removal of the
dilated segment of colon. Grossly, the resected colon had a
proximal diameter of 6.5 cm and a distal diameter of
16 cm. Microscopically, there was hypoganglionosis throughout the
resected sigmoid colon. A section from the distal resected colon at
the rectosigmoid junction demonstrated focal aganglionosis
involving the surgical margin with associated hypertrophy of the
muscularis. There may be additional aganglionic colon incorporated
into the Hartmann's pouch, which can be confirmed after the pouch
is resected to allow completion of the operation with
Hirschsprung's disease (congenital colonic aganglionosis) is a
condition normally associated with newborns and infants. It can
present in the newborn period as a failure to pass meconium in the
first 24 hours of life.
In infants and toddlers it is associated with a history of
constipation, abdominal distention, and failure to thrive.
The degree of aganglionosis can be quite variable, with some
patients having aganglionosis of just the internal anal sphincter
(termed ultrashort-segment Hirschsprung's disease) and some having
aganglionosis of the entire colon.
The majority of patients with this condition fall between these
extremes. The incidence of Hirschsprung's disease is 1 in 4000 live
births, with males affected 4 times more frequently than females.
The differential diagnosis of megacolon is broad, so classifying
the various causes as either congenital or acquired is helpful.
Congenital causes include Hirschsprung's disease, the neuronal
intestinal dysplasias, myelodysplasia, and anorectal malformations.
In adults, megacolon is usually from an acquired cause, since
congenital causes are usually diagnosed in childhood. Acquired
causes of megacolon can be further subclassified by the underlying
mechanism. Neurologic causes include Chaga's disease, central
nervous system dysfunction, diabetic neuropathy, and myotonic
dystrophy. Diseases affecting smooth muscle, such as scleroderma
and amyloidosis, can also cause megacolon, as can certain metabolic
disorders and drugs. Finally, acquired megacolon can be idiopathic
(Ogilvie's syndrome) or secondary to mechanical obstruction.
Diagnosis of Hirschsprung's disease in the pediatric population
is best made using rectal manometry and rectal suction biopsy.
Rectal manometry involves measuring the tone of the anal sphincter
while a balloon is inflated in the rectum. In suction biopsy,
specimens of mucosa and submucosa are obtained to evaluate for the
presence of ganglion cells and for histochemical staining. This
specimen should be taken at least 3 cm proximal to the dentate line
to avoid an area of normal hypoganglionosis.
In adults, diagnostic imaging in the form of an abdominal series
and a barium enema precedes biopsy. Classically, the barium enema
would reveal a narrowed rectum, representing the aganglionic
segment, distal to the dilated sigmoid. A cone-shaped zone of
transition may be present, best visualized in the lateral
These classic findings may be absent in disease limited to the
external anal sphincter.
Treatment of Hirschsprung's disease involves surgical removal of
the defective segment of the colon.
The diagnosis and operative repair are usually made before the
patient reaches age 5. The original operative repair was described
in 1948 and is termed the Swenson procedure. Though there have been
several modifications to the original Swenson procedure, operative
repair generally involves resecting the aganglionic segment of
colon, using frozen sections to determine the proximal extent of
the aganglionosis, and creating an anastomosis between the normally
innervated bowel and the anal canal.
The prognosis after surgery is good, and the majority of patients
achieve fecal continence.
In the appropriate clinical setting, Hirschsprung's disease
should be considered in the differential diagnosis of an adult with