med 18

 

• Nonabdominal conditions including strep pharyngitis

and pneumonia often present with abdominal pain.

Intussusception. This is a telescoping of bowel into a

proximal segment. In young children 2 months to 2 years

old, the condition is usually idiopathic, and the most

common location is ileocolic. Over the age of 3 years, a

lead point such as a polyp or Meckel diverticulum may be

the culprit. The typical presentation is intermittent

colicky abdominal pain of a few minutes' duration associated with vomiting. These episodes of pain are followed

by periods of lethargy. Unfortunately, the classic triad of

symptoms-currant jelly stools, vomiting, and colicky

abdominal pain-occurs in only 20% of patients. Physical

exam may reveal an empty right lower quadrant and nontender mass in the right upper quadrant. Prolonged

duration leads to bowel ischemia and necrosis. HenochSchonlein purpura is associated with ileo-ileal intussusception. Because of this unusual location, it is neither

visualizable nor reducible by standard methods and

requires computed tomography (CT) scan and surgical

reduction.

Meckel diverticulum. The most common congenital

abnormality of the gastrointestinal tract, Meckel diverticulum is the remnant of the vitelline duct. In half of all cases

there is ectopic tissue (usually gastric). Painless rectal

bleeding is the most common presentation of Meckel, but

other symptoms include abdominal pain, nausea, and

vomiting. The rules of 2s is a good way to classify the condition (Table 50-1).

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ABDOMINAL PAIN

Table 50-1 . Meckel diverticu lum and rule of 2s.

2% of the population

2 years old most common age of presentation

2 inches long

2 feet from the ileocecal valve

2 types of ectopic tissue (gastric and pancreatic)

Malrotation and volvulus. This entity refers to abnormal intrauterine rotation and fixation of bowel within the

abdomen. This abnormal development around a narrow

mesenteric pedicle puts the bowel at risk of twisting

around these vessels and subsequent bowel necrosis.

Classic symptoms include bilious vomiting, abdominal

pain, distention, and bloody diarrhea.

Appendicitis. Although uncommon in young children, more than 80% present after the appendix has

ruptured. Their presentation is often atypical, with a

high rate of diarrhea and absence of typical migration

of pain.

� Medical Causes of Abdominal Pain

Constipation. Constipation is particularly common in

toddlers around potty training age. Symptoms include

diffuse colicky abdominal pain, anorexia, hard stools,

and straining. Constipation can be confused with intussusception because of the intermittent nature of the

pain.

Gastroenteritis. This entity is prevalent in childhood,

particularly in those children in daycare. The most likely

agents are viral; bacterial should be considered in those

with bloody diarrhea. Pain is associated with abdominal

cramping. Fever, vomiting, diarrhea, and pain are all

symptoms of the condition. Appendicitis particularly

early in the course of illness is often mistaken for acute

gastroenteritis.

CLINICAL PRESENTATION

� History

A careful, detailed history is essential in the evaluation of

the pediatric patient with abdominal pain. Questions

should be asked of both the caregiver and child. Most preschoolers over the age of 3 or 4 years old can provide reliable information. Inquire about the location of pain

(diffuse vs. localized) and whether it has remained consistent or migrated (as in the case of appendicitis from peri ­

umbilical to right lower quadrant). The duration of the

pain is essential to distinguish between acute and chronic

conditions. Ask about associated symptoms such as vomiting (bloody, bilious, projectile, post prandial), diarrhea

(bloody, currant jelly), anorexia, dysuria, and fever (height

and duration).

� Physical Examination

Before focusing on the abdomen, a thorough physical

examination is necessary to rule out extraabdominal

conditions, which can present with abdominal pain.

Assess the pharynx for exudate and skin for the stereotypical sandpaper rash, as strep pharyngitis and scarlet fever

can produce diffuse abdominal pain. Carefully examine the

lower extremities and buttocks for the characteristic

purpuric lesions of Henoch-SchOnlein purpura, which can

produce abdominal pain and ileo-ileal intussusception.

Auscultate the lungs, as lower lobe pneumonia will irritate

the diaphragm, resulting in pain that may even overshadow the cough. A thorough genitourinary evaluation is

necessary to rule out genitourinary causes, including

testicular torsion and hernias.

Delicate palpation of the abdomen to assess for focal

tenderness and masses will often narrow the differential

diagnosis. A firm mass in the left lower quadrant or mid

abdomen supports the clinical picture of constipation, as

does hard stool on rectal exam. An olive-shaped mass in

the epigastrium of a newborn with postprandial vomiting

is pathognomonic of pyloric stenosis. Examination

should include abdominal auscultation and assessment of

tenderness, rebound, and guarding. Asking the child

"where does it hurt the most?" and "can you show me

with one finger?" enlists assistance and allows accurate

identification of the most distressing location of pain.