Comprehensive Study Guide: Pediatric Gastrointestinal Disorders

Pyloric Stenosis (Leifer, p. 661)

• Definition and Pathophysiology: Pyloric stenosis is an obstruction of the lower end of the stomach (pylorus) caused by the overgrowth (hypertrophy) of the circular muscles of the pylorus or spasms of the sphincter. This results in progressive narrowing and eventual occlusion of the pyloric lumen.
• Classification and Timing: While it is commonly classified as a congenital anomaly, the condition is notably not present at birth. Symptoms typically do not manifest until the infant is between $2$ and $3$ weeks old.
• Epidemiology:
  • It is considered the most common surgical condition of the gastrointestinal (GI) tract in infancy.
  • Incidence rates are significantly higher in male infants compared to females.
  • There is a noted correlation between the occurrence of pyloric stenosis and infants with hyperbilirubinemia.

Clinical Manifestations of Pyloric Stenosis

• Projectile Vomiting: This is the outstanding and hallmark symptom of the condition. It occurs with significant force or pressure being exerted on the pylorus immediately after eating.
• Vomitus Characteristics: The vomitus consists mainly of mucus and ingested milk; it does not typically contain bile as the obstruction is above the bile duct.
• Hunger and Feeding: Despite vomiting, the infant remains constantly hungry and will typically eat again immediately after an episode of vomiting.
• Physical Findings:
  • Olive-shaped Mass: A palpable, "olive-shaped" mass can often be felt in the upper right quadrant of the abdomen.
  • Peristaltic Waves: Visible peristaltic waves may be observed moving from left to right across the abdomen when the infant is lying supine.
  • Physical Deterioration: The infant will experience failure to gain weight and symptoms of dehydration.
• Pain Level: There is generally no evidence of actual pain associated with this condition, despite the forceful vomiting.

Diagnostic and Nursing Interventions for Pyloric Stenosis

• Diagnostic Imaging: Structural confirmation is achieved through abdominal ultrasound, which visualizes the elongated mass surrounding the pyloric area and the hypertrophy of the pyloric muscle.
• Surgical Treatment: The definitive treatment is a pyloromyotomy, a procedure where an incision is made into the pyloric muscle to allow the inner lining to bulge through, thereby widening the lumen.
• Nursing Care and Pre/Post-Operative Interventions:
  • Vomiting Management: Position the child on her side or with the head elevated during vomiting to prevent aspiration. Document the amount and specific characteristics of all vomitus.
  • Fluid Management: Monitor intravenous (IV) fluid replacement closely. Monitor fluid and electrolyte balance for any deficits. Perform daily weights and track Intake and Output ($I/O$).
  • Nutrition and Diet: Maintain $NPO$ (nothing by mouth) status until bowel sounds return post-surgery. Start a clear liquid diet $4-6$ hours after surgery, then advance to breast milk or formula as tolerated.
  • Decompression: Monitor the Nasogastric ($NG$) tube used for stomach decompression.
  • Elimination: Monitor the type, number, and characteristics of stools, as well as the color and frequency of urine.

Hirschsprung’s Disease (Congenital Aganglionic Megacolon)

• Description: Hirschsprung’s disease occurs when a section of the colon is aganglionic, meaning it lacks ganglionic innervation. This absence of nerves results in decreased motility in that segment, leading to a functional obstruction.
• Primary Location: Usually affects the lower portion of the sigmoid colon, leading to a "shrunken rectum" appearance below a "swollen colon."
• Manifestations by Age:
  • Newborns: Failure to pass meconium within the first $24-48$ hours of life, refusal to eat (feeding intolerance), episodes of vomiting bile, and significant abdominal distention.
  • Infants: Chronic constipation, abdominal distention, and intermittent episodes of vomiting and diarrhea.
  • Older Child: Persistent constipation, abdominal distention, visible peristalsis, characteristic ribbon-like stools, a palpable fecal mass, and a malnourished physical appearance.
• General Symptoms: Swelling around the belly, greenish-brown vomitus, flatulence, failure to gain weight, and severe fatigue.
• Treatment and Nursing Care:
  • The impaired, aganglionic part of the colon is surgically removed followed by an anastomosis of the healthy intestine.
  • In newborns, a temporary colostomy may be necessary to allow the bowel to rest.
  • Nursing focus includes monitoring for signs and symptoms of dehydration.

Intussusception

• Definition: A life-threatening disorder where one part of the intestine slips (telescopes) into another part immediately below it. If not treated within $24$ hours, the prognosis worsens, though the prognosis is generally good with early intervention.
• Pathophysiology: The telescoping can progress to ischemia (lack of blood flow) of the affected bowel segment.
• Epidemiology: Primarily common in infants and children aged $3$ months to $6$ years old.
• Clinical Manifestations:
  • Pain Cycles: Intervals of sudden, severe abdominal pain; the child may appear completely normal between these episodes.
  • Physical Signs of Distress: Loud crying, straining efforts, and the characteristic kicking and drawing of the legs toward the abdomen.
  • Physical Exam: A palpable sausage-shaped mass in the right upper quadrant of the abdomen. The lower right quadrant may feel empty, a sign known as the Dance Sign. The abdomen may be tender and distended.
  • Currant Jelly Stools: Stools mixed with blood and mucus, resembling the consistency and appearance of red currant jelly.
  • Severe Complications: High fever reaching up to $106.0^{\circ}F$ and a hard, rigid abdomen.

Celiac Disease (Gluten Enteropathy / Sprue)

• Definition: An inherited condition and leading malabsorption problem in children where the body cannot process gluten, a protein found in certain grains.
• Pathophysiology: Environment triggers stimulate immune system antibodies to attack and damage the lining of the small intestine. This repeated exposure damages the villi (tiny projections) and microvilli on the endothelial cells of the intestinal wall, preventing the absorption of nutrients and leading to malnutrition.
• Clinical Manifestations:
  • Symptoms are not evident until the infant is between $6$ months and $2$ years of age, coinciding with the introduction of gluten-containing foods.
  • Physical Profile: Failure to thrive ($FTT$) in children, characterized by a bloated/distended belly and atrophy of the buttocks (wasting of muscle).
  • Stool Characteristics: Diarrhea or steatorrhea (excess fat in stool). Stools are large, bulky, and frothy due to undigested contents. Typically involve $2-4$ bowel movements daily.
  • Other Symptoms: Loss of appetite, weight loss, emaciation, and skin rashes.
• Diagnosis and Treatment:
  • Diagnosis: Confirmed by a serum Immunoglobin A ($IgA$) test and a small bowel biopsy.
  • Treatment: A strict, lifelong diet restricted in wheat, barley, oats, and rye. Adherence is critical, as long-term bowel pathology can occur if dietary compliance is not lifelong.

Clinical Indicators of Stool Coloration

• Brown: Normal coloration; result of bile produced in the liver.
• Green: Indicates food moving through the large intestine too quickly, or consumption of green leafy vegetables/green food coloring.
• Yellow: Greasy, foul-smelling yellow stool indicates excess fat, often a sign of a malabsorption disorder such as Celiac disease.
• Black: May indicate internal bleeding due to an ulcer or cancer. It can also be caused by vitamins containing iron or bismuth subsalicylate. Sticky black stool warrants immediate medical attention.
• Light-colored / White / Clay-colored: Indicates a potential bile duct obstruction or can be a side effect of certain medications. This requires medical consultation.
• Blood-stained or Red: Bright red blood in the stool can be a symptom of cancer or other serious conditions and always requires immediate medical evaluation.