Pediatric Gastrointestinal Disorders

A 14-day-old term male infant is brought to the emergency department due to acute onset of irritability and three episodes of bright green emesis over the past 4 hours. The infant was born at 39 weeks gestation without complications and had been feeding well until today. Vital signs are within normal limits for age. Physical examination reveals a soft, non-distended abdomen without palpable masses, guarding, or erythema. There is no hemodynamic instability. Assuming this patient proceeds through standard evaluation and requires surgical intervention for the most likely underlying etiology without evidence of bowel perforation at any stage, arrange the following diagnostic and therapeutic steps in the correct chronological sequence.

A 4-week-old boy is brought to the emergency department by his parents due to a 3-day history of worsening vomiting. The parents report that he forcefully vomits a large amount of milk immediately after almost every feed. The vomitus does not contain bile. Despite the vomiting, the infant appears hungry and eagerly accepts feeds right after an episode. He has had only one wet diaper in the past 12 hours. Vital signs are temperature 37.0°C (98.6°F), heart rate 165/min, blood pressure 70/40 mm Hg, and respiratory rate 40/min. Physical examination reveals a sunken anterior fontanelle, dry mucous membranes, and markedly decreased skin turgor. Palpation of the abdomen reveals a firm, mobile, olive-shaped mass in the right upper quadrant. Laboratory studies are obtained and show the following:

Which of the following is the most appropriate next step in the management of this patient?

A 9-month-old girl is brought to the emergency department due to intermittent episodes of severe crying. During these episodes, she draws her legs up to her chest and appears to be in significant pain. Between episodes, she is calm and plays with her toys. Her parents report one episode of nonbilious emesis and note that her most recent diaper contained dark red, mucus-like stool. Her vital signs are stable, and abdominal examination reveals a palpable sausage-shaped mass in the right upper quadrant without guarding or rebound tenderness. Arrange the following steps in the standard chronological order of management for this patient.

A 2-year-old boy is brought to the pediatric clinic by his parents after they noticed a large amount of dark red blood in his diaper this morning. The parents report the child has been entirely asymptomatic otherwise; he has had no fever, vomiting, abdominal pain, diarrhea, or changes in his appetite. His medical history is unremarkable, and he has reached all developmental milestones appropriately. Vital signs are within normal limits for his age. Physical examination reveals a soft, non-tender abdomen with normal active bowel sounds. Rectal examination shows dark blood in the vault but no anal fissures, skin tags, or palpable masses. Which of the following is the most appropriate next diagnostic test for this patient?

Match each classic clinical or imaging finding with its corresponding pediatric gastrointestinal diagnosis.

Parents arrive at the triage desk with their 14-day-old male infant, reporting that he suddenly began vomiting dark green fluid 4 hours ago. Previously, the infant had been breastfeeding well and passing normal transitional stools. On triage assessment, the infant appears lethargic and pale. Vital signs reveal a heart rate of 195/min, respiratory rate of 65/min, and blood pressure of 55/30 mm Hg. Physical examination demonstrates a rigid, distended abdomen with diffuse guarding and absent bowel sounds. Capillary refill time is 5 seconds. An emergency portable abdominal radiograph shows a paucity of gas in the distal bowel. What is the most appropriate next step in the management of this patient?

A 2-day-old full-term neonate is evaluated in the nursery for failure to pass meconium and progressive abdominal distension. Physical examination reveals a remarkably tight anal sphincter. Upon withdrawal of the examiner's finger during a digital rectal examination, there is an explosive release of gas and foul-smelling stool. Arrange the following steps in the optimal diagnostic and therapeutic sequence for this patient's suspected condition.

A 4-week-old boy is brought to the pediatric emergency department with a 12-hour history of high fever, progressive lethargy, and explosive, foul-smelling, bloody diarrhea. His parents report that his abdomen has become massively swollen over the past day. His neonatal history is notable for passage of meconium at 50 hours of life and chronic constipation requiring glycerin suppositories. Vital signs show a temperature of 39.1°C (102.4°F), heart rate of 185/min, respiratory rate of 60/min, and blood pressure of 65/35 mm Hg. Physical examination reveals a lethargic, mottled infant with a markedly distended and tympanic abdomen. Digital rectal examination results in a forceful expulsion of foul-smelling stool and gas. Arrange the following management steps in the most appropriate chronological sequence for this patient.

An 11-week-old male infant is brought to the pediatric clinic by his parents because he has not had a bowel movement for the past six days. The parents report that his stools are typically small and hard, and his abdomen frequently appears bloated. They mention that after birth, he did not pass his first stool until he was almost two days old. The infant is exclusively formula-fed. Vital signs are within normal limits for his age. Physical examination demonstrates a distended but soft abdomen with normoactive bowel sounds. Digital rectal examination reveals a tight anal sphincter. Upon withdrawal of the examiner's finger, there is an explosive release of gas and foul-smelling stool. Which of the following is the most definitive test to confirm the diagnosis in this patient?

Match each classic clinical scenario to the most appropriate pediatric gastrointestinal diagnosis.

The neonatal intensive care unit team is called to assess a 36-hour-old full-term male who developed progressive abdominal distension and bilious emesis. He has not produced any meconium since birth. The infant was delivered vaginally at 39 weeks gestation to a 32-year-old mother whose pregnancy was complicated by poorly controlled gestational diabetes mellitus. His birth weight was 4.2 kg (9 lb 4 oz). Vital signs are within normal limits for age. Physical examination reveals a markedly distended and tympanitic abdomen without palpable masses, erythema, or tenderness. The anus is patent. An abdominal radiograph shows multiple dilated bowel loops with air-fluid levels and a paucity of distal gas. A water-soluble contrast enema is performed, revealing an abrupt transition in bowel caliber at the splenic flexure; the colon proximal to the splenic flexure is significantly dilated, while the descending colon and sigmoid colon are of uniformly small caliber. During the procedure, the infant passes a large meconium plug followed by copious amounts of stool and flatus, resulting in immediate relief of his abdominal distension. Which of the following is the most appropriate next step in the management of this patient?

An anxious mother brings her 5-week-old firstborn son to the pediatrician's office because he has been vomiting for the past five days. She notes that the vomiting occurs immediately after every feeding, is very forceful, and consists of curdled breast milk without any green or yellow discoloration. Despite the vomiting, the infant cries continuously and appears ravenously hungry, eagerly demanding to be fed again. On physical examination, the infant has slightly dry mucous membranes and a sunken anterior fontanelle. Palpation of the abdomen reveals a firm, mobile, 2-cm ovoid mass in the right upper quadrant. Which of the following is the most appropriate initial diagnostic test to confirm this patient's underlying condition?

During a pediatric gastroenterology case conference, a series of complex patient presentations is reviewed. For each atypical or highly specific clinical vignette described below, identify the correct underlying embryologic or pathophysiologic mechanism.

A 6-week-old female infant is brought to the clinic for a well-child visit. Her parents report that she is exclusively breastfed and feeding well, but they have noticed her skin appearing increasingly yellow over the past two weeks. Additionally, her stools have recently become very pale, resembling the color of clay. Physical examination is notable for scleral icterus, generalized jaundice, and a palpable liver edge 2 cm below the right costal margin. Arrange the following steps in the most appropriate chronological sequence for the standard evaluation and definitive management of this patient's suspected condition.

A 6-month-old male infant is brought to the emergency department by his parents due to repetitive, profuse vomiting and extreme lethargy. The vomiting began approximately 2 hours after he was fed oat cereal for the first time. The parents note that he became remarkably pale and limp shortly after the vomiting started. He was born at term and has previously tolerated breast milk and pureed vegetables without issue. His temperature is 36.5°C (97.7°F), heart rate is 185/min, blood pressure is 60/35 mmHg, and respiratory rate is 45/min. Physical examination reveals a lethargic, mottled infant with delayed capillary refill of 5 seconds. There is no rash, urticaria, or facial swelling. The lungs are clear to auscultation bilaterally without wheezing. The abdomen is soft, non-distended, and non-tender, with hyperactive bowel sounds.

Laboratory studies show:
Leukocyte count: $24,500/\text{mm}^3$ (with 18% bands)
Hemoglobin: $11.5 \text{ g/dL}$
Platelets: $550,000/\text{mm}^3$
Arterial blood gas:
pH: $7.28$
$pCO_2$: $35 \text{ mm Hg}$
$HCO_3^-$: $16 \text{ mEq/L}$

Which of the following is the most appropriate initial management for this patient?

Match each classic pediatric clinical presentation with the most likely underlying gastrointestinal diagnosis.

Parents bring their 24-month-old son to the outpatient clinic after noticing a large amount of maroon-colored stool in his diaper earlier today. The child has no history of fever, abdominal pain, diarrhea, or vomiting. He is currently playing comfortably in the examination room. Vital signs show a heart rate of 105/min, respiratory rate of 24/min, and blood pressure of 90/55 mm Hg. Physical examination reveals a soft, non-tender abdomen with normal active bowel sounds and no palpable masses. Inspection of the perianal area shows no fissures, but residual maroon-colored stool is present on the examining glove. Which of the following is the most appropriate next diagnostic step to establish the underlying cause of this patient's bleeding?

A 2-year-old child is brought to the emergency department after passing a massive volume of painless, dark red stool at home. On examination, the patient appears pale, mottled, and lethargic. Vital signs reveal a heart rate of 165/min, respiratory rate of 28/min, and blood pressure of 70/40 mmHg. Capillary refill time is prolonged at 4 seconds. The abdomen is soft, non-distended, and non-tender to palpation. Arrange the following medical interventions in the most appropriate chronological sequence for the evaluation and management of this patient.

A 9-month-old male infant is brought to the emergency department due to sudden episodes of severe, inconsolable crying during which he draws his legs up to his abdomen. Between episodes, he appears lethargic but calm. The parents report one episode of dark, bloody, mucus-like stool on the way to the hospital. He is tachycardic but normotensive, and the abdomen is soft with a palpable 'sausage-shaped' mass in the right upper quadrant. Arrange the following steps in the correct chronological sequence for the evaluation and management of this patient.

An $8$-day-old male infant is brought to the emergency department via ambulance after several episodes of dark green vomiting. The mother reports that the infant has been increasingly lethargic over the past $12$ hours and has not produced a wet diaper since yesterday. Vital signs include a temperature of $35.4^\circ \text{C}$ ($95.7^\circ \text{F}$), heart rate of $195$/min, respiratory rate of $65$/min, and blood pressure of $52/28$ mm Hg. Physical examination reveals an ill-appearing, mottled infant. The abdomen is markedly distended and exquisitely tender to palpation, demonstrating involuntary guarding. A localized area of cutaneous erythema and edema is noted extending across the right hemiabdomen. The skin over the trunk shows scattered blanching erythematous macules with central yellow papules, which the mother states have been present since hospital discharge. Capillary refill is $5$ seconds. Arterial blood gas analysis on room air shows a pH of $7.20$, $\text{pCO}_2$ of $20$ mm Hg, and $\text{HCO}_3^-$ of $8$ mEq/L. Which of the following is the most appropriate next step in the management of this patient?