early in the postoperative course or months or even years later. The child often
has the sudden onset of abdominal cramps, nausea, vomiting, and abdominal
distension. Although most intestinal obstructions from adhesions do not
jeopardize the perfusion of the bowel, occasionally a loop of intestine, caught
under a fibrous band or herniating through the adhesion, can become gangrenous.
All such patients need to be admitted to the hospital and evaluated by a surgeon
who should direct the complete management.

Chronic Partial Intestinal Obstruction
Any child with intermittent abdominal distension, nausea, anorexia, occasional
vomiting, or chronic constipation or obstipation may have partial intestinal
obstruction. A number of diagnostic considerations exist.
TABLE 116.3
DIFFERENTIAL DIAGNOSIS OF FUNCTIONAL CONSTIPATION AND
HIRSCHSPRUNG DISEASE
Functional constipation

Hirschsprung disease

Onset
History

<2 yrs
Coercive training
Colicky abdominal pain
Periodic volume stools

Encopresis
Abdominal
distension
Rectal examination

Barium
examination
Motility
Biopsy

Present
Absent or minimal

Birth
Enemas necessary
No abdominal pain
Episodes of intestinal
obstruction
Absent
Present

Feces-packed rectum
Dilated rectum

Empty rectum
Narrow segment

Normal
Ganglion cells

Abnormal
No ganglion cells

Chronic Constipation
Chronic constipation is probably one of the most common causes for abdominal

pain, distension, and vomiting in children. The history, if available from a reliable
parent, may attest to chronic constipation; however, occasionally, such a child is


diagnosed only by palpating a large mass through the intact abdominal wall or a
hard fecal mass blocking the anal outlet on rectal examination. Such children may
have a history of encopresis and appear malnourished. Chapter 18 Constipation
covers the diagnostic approach to the child with constipation.
These children should be disimpacted with enemas through a rectal tube passed
above the obstruction, or, if necessary, disimpacted manually. For children unable
to tolerate disimpaction, or those with significant constipation following rectal
disimpaction, oral or nasogastric bowel evacuants such as polyethylene-glycol
electrolyte solution can be used. If the process has progressed to partial bowel
obstruction, either ED or inpatient management is necessary to clean out the
bowel adequately.

Aganglionic Megacolon (Hirschsprung Disease)
In patients with Hirschsprung disease, the parasympathetic ganglion cells of
Auerbach plexus between the circular and longitudinal muscle layers of the colon
are absent. The involved segment varies in length, from less than 1 cm to
involvement of the entire colon and small bowel. The effect of this absence of
ganglion cells produces spasm and abnormal motility of that segment, which
results in either complete intestinal obstruction or chronic constipation.
These children have a lifelong history of constipation, so it is important to
obtain an accurate account of the child’s stool pattern from birth. A child with
Hirschsprung disease typically has never been able to stool properly without
assistance (e.g., enemas, suppositories, anal stimulation). Normal stooling is not
possible because of the failure of the aganglionic bowel and internal anal
sphincter to relax. The child usually has no history of encopresis, as one would
find in chronic functional constipation. These children have chronic abdominal

distension and are often malnourished. Vomiting is uncommon, as are other
symptoms. Complete intestinal obstruction in Hirschsprung disease is more likely
to occur in early infancy and only rarely in the older age groups. It may present
with signs and symptoms of acute bowel perforation.
Table 116.3 summarizes the pertinent diagnostic features differentiating
functional constipation from Hirschsprung disease.
After flat and upright abdominal roentgenogram radiographic studies have
been obtained, a properly performed barium enema with a Hirschsprung catheter
is the best initial diagnostic procedure. There should be no preparation of the
bowel. Ideally, the rectum should not be stimulated by enemas or digital
examination for 1 to 2 days before the procedure. The key to diagnosis is seeing a
“transition zone” ( Fig. 116.16 ) between the contracted aganglionic bowel and
the proximal dilated ganglionated bowel. Stimulation of the rectum shortly before


the study may result in decompression of the proximal bowel, with loss of
definition of the transition zone. When a clear-cut transition zone is seen, it is not
necessary to fill the colon with barium more than 12 to 18 in. above the transition
point. However, it is important not to empty the colon of barium at the end of the
study. The presence of retained barium above the transition point 24 hours later
strongly suggests the diagnosis of Hirschsprung disease.

FIGURE 116.16 Hirschsprung disease. Barium enema studies in lateral view show transition
zone (arrow ) with narrow rectum but dilated sigmoid colon.

Anorectal manometry to determine the presence or absence of relaxation of the
internal anal sphincter is helpful in establishing the neurogenic dysfunction of the
bowel. Barium enema studies and manometry are clearly complementary in the
diagnosis of Hirschsprung disease. However, rectal manometric studies are more
reliable than radiologic methods for short aganglionic segments that are usually

not apparent on barium enema studies. Manometric studies are not dependable in
infants younger than 3 weeks of age. If the barium enema and anal manometry


studies indicate Hirschsprung disease, rectal biopsy is not necessary to confirm
the diagnosis.
In children of all ages, an adequately performed suction mucosal biopsy of the
rectum 2 cm or more above the dentate line can be reliable in diagnosing
Hirschsprung disease. Because of the complicated evaluation and management of
this disease, referral to a pediatric surgeon is recommended.

Duplications
Duplications occur anywhere from the mouth to the anus and produce various
symptoms. In the abdomen, there may be a noncommunicating cyst that gradually
fills up with secretions and compresses the adjacent normal bowel, producing a
palpable abdominal mass or chronic intestinal obstruction. Rarely, a marginal
ulcer resulting from ectopic gastric mucosa may occur, and this produces painless
bleeding. After appropriate radiographic diagnosis, surgery is indicated.

Inflammatory Bowel Disease
The older child or adolescent may develop either Crohn disease or ulcerative
colitis (see Chapter 91 Gastrointestinal Emergencies ), and this must be included
in the differential diagnosis of chronic intestinal obstruction. Usually, the child
has a history of changing bowel habits, with mucus or blood in the stools, chronic
abdominal pain, and weight loss. Chapter 91 Gastrointestinal Emergencies covers
inflammatory bowel disease in detail.

DISEASES THAT PRODUCE RECTAL BLEEDING
Goals of Treatment
Rectal bleeding can be a sign of a serious condition. Clinicians need to identify

generally innocent etiologies from those that can be life-threatening. The primary
goals should be early recognition of hemorrhagic shock and ischemic bowel.
Blood on the outside of a formed stool is likely to originate from the distal large
bowel, rectum, or anus. Blood mixed in the stool is generally from a higher
source of bleeding. Blood associated with diarrhea is common with inflammatory
bowel disease and infectious enteritis. A “tarry” stool suggests a source of
bleeding in the proximal portion of the GI tract, and bright red blood suggests a
more distal origin ( Fig. 116.17 ). All patients with rectal bleeding should have a
rectal examination. Those with significant hemorrhage require flexible
colonoscopy. In some patients, no definite diagnosis may be reached despite
extensive studies. In any patient with significant bleeding, however, surgical
consultation is indicated. Chapters 33 Gastrointestinal Bleeding and 91