Gastroenterology Practice Questions

Q: A 6-week-old infant presents with projectile, non-bilious vomiting after feeds and poor weight gain. On examination, the infant appears eager to feed and has visible gastric peristalsis. What is the most likely diagnosis?

Pyloric stenosis. ***Pyloric stenosis*** - This condition is characterized by **projectile, non-bilious vomiting** in young infants, classically presenting between **2-8 weeks of age**. - **Visible gastric peristalsis** (peristaltic waves moving from left to right across the upper abdomen) is a pathognomonic sign. - The infant appears **eager to feed** after vomiting, distinguishing it from other causes where the infant is typically lethargic and refuses feeds. - An **olive-shaped mass** may be palpable in the right upper quadrant (hypertrophied pylorus). *Intussusception* - While it can manifest with vomiting and poor feeding, **intussusception** typically presents with sudden onset of **severe, crampy abdominal pain** (drawing legs up, inconsolable crying) and **currant jelly stools**. - The peak incidence is between **6-36 months**, making it less likely in a 6-week-old infant. - Vomiting may be bilious, and lethargy occurs later as a sign of shock. *Hirschsprung disease* - This condition primarily presents with **delayed passage of meconium** (beyond 48 hours) in neonates and chronic **constipation** with **abdominal distension**. - Vomiting, when present, is typically **bilious** due to intestinal obstruction. - Not associated with projectile, non-bilious vomiting or visible peristalsis. *Necrotizing enterocolitis* - **Necrotizing enterocolitis (NEC)** is predominantly a disease of **premature infants**, especially those with very low birth weight. - Key features include **bilious vomiting**, **bloody stools**, **abdominal distension**, and signs of **sepsis** (temperature instability, apnea, lethargy). - Very rare in healthy, full-term infants at this age.

Q: A 6-month-old infant presents with failure to thrive and chronic diarrhea. Examination reveals a distended abdomen. Which condition is most likely?

Cystic fibrosis. ***Cystic fibrosis*** - **Failure to thrive**, **chronic diarrhea** (due to pancreatic insufficiency leading to malabsorption), and **abdominal distension** are classic symptoms in infants with cystic fibrosis. - The thick, sticky mucus produced in CF obstructs pancreatic ducts, preventing the release of digestive enzymes. - CF is one of the most common causes of malabsorption presenting in early infancy. *Celiac disease* - While celiac disease can cause **failure to thrive** and **diarrhea**, it typically manifests later when gluten is introduced into the diet (around 6-12 months of age or later). - At 6 months, many infants may not yet have been exposed to gluten-containing foods. - A distended abdomen can occur, but celiac disease does not involve pancreatic insufficiency, which is the hallmark of CF-related malabsorption. *Lactose intolerance* - **Lactose intolerance** can cause diarrhea and abdominal distension, but primary lactose intolerance is extremely rare in infants. - Secondary lactose intolerance can occur but typically does not lead to severe **failure to thrive** or the chronic, severe malabsorption seen in this case. - This presentation is more consistent with pancreatic insufficiency rather than isolated lactase deficiency. *GERD* - **Gastroesophageal reflux disease (GERD)** commonly causes spitting up, vomiting, and irritability, which can indirectly lead to poor weight gain. - However, severe **chronic diarrhea** and marked abdominal distension are not typical primary symptoms of GERD. - GERD does not cause malabsorption or the gastrointestinal symptoms described in this case.

Q: A 7-year-old boy presents with recurrent episodes of abdominal pain, diarrhea, and failure to thrive. Laboratory findings show anti-tissue transglutaminase antibodies. What is the most likely diagnosis?

Celiac disease. ***Celiac disease*** - The constellation of **abdominal pain**, **diarrhea**, **failure to thrive**, and specifically **positive anti-tissue transglutaminase (tTG) antibodies** is highly indicative of celiac disease. - **Anti-tTG antibodies** are a sensitive and specific marker for celiac disease, which is an autoimmune disorder triggered by gluten consumption. *Crohn's disease* - While it can cause abdominal pain, diarrhea, and failure to thrive, it typically involves **transmural inflammation** and can affect any part of the gastrointestinal tract. - It is not associated with **anti-tTG antibodies**; instead, it might show elevated **ESR/CRP** and sometimes **anti-Saccharomyces cerevisiae antibodies (ASCA)**. *Ulcerative colitis* - This condition primarily presents with **bloody diarrhea** and **colonic inflammation** starting in the rectum and extending proximally. - It is also not associated with **anti-tTG antibodies** and is characterized by different inflammatory markers and endoscopic findings. *Lactose intolerance* - Primarily causes **abdominal pain**, **bloating**, and **diarrhea** after consuming dairy products due to lactase deficiency. - It does not cause **failure to thrive** or involve **anti-tTG antibodies**, and its symptoms are usually relieved by avoiding lactose.

Q: A young child presents with a palpable mass in the lower right quadrant. Imaging confirms intussusception. Which part of the intestine most commonly acts as the intussusceptum (telescoping segment)?

Ileum. ***Ileum*** - The **ileocolic region** is the most common site for intussusception in children (60-80% of cases), where the **ileum acts as the intussusceptum** (telescoping segment) that invaginates into the cecum/colon (intussuscipiens). - This is particularly true in children aged 6 months to 3 years, often linked to **hypertrophied Peyer's patches** acting as a lead point. - The classic presentation includes a **palpable "sausage-shaped" mass** in the right upper quadrant and **"currant jelly" stools**. *Duodenum* - Duodenal intussusception is **extremely rare** and accounts for less than 1% of cases. - When it occurs, it is usually associated with specific pathological lead points such as **polyps, tumors, or duplication cysts**. *Jejunum* - Jejunojejunal intussusception is possible but **much less frequent** than ileocolic type. - It typically occurs in association with a **pathological lead point** such as Meckel's diverticulum, polyp, or lymphoma. - More common in older children when a lead point is identified. *Colon* - While the colon (cecum) serves as the **receiving segment (intussuscipiens)** in the most common ileocolic type, primary **colocolic intussusception** is relatively uncommon in children. - Colocolic intussusception often suggests a **pathological lead point** such as a polyp, lymphoma, or other mass lesion.

Q: A 6-month-old infant presents with recurrent episodes of sudden-onset crying, drawing up of the legs, and currant jelly stools. What is the most likely diagnosis?

Intussusception. ***Intussusception*** - The classic triad of **sudden-onset intermittent abdominal pain** (crying and drawing up legs), **vomiting**, and **currant jelly stools** (blood and mucus) is highly indicative of intussusception. - This condition is the most common cause of **intestinal obstruction** in infants between 6 months and 3 years of age, often presenting with a **sausage-shaped abdominal mass**. *Volvulus* - Volvulus typically presents with **bilious vomiting** and **abdominal distension**, indicating intestinal obstruction and ischemia. - While it causes acute abdominal pain, the characteristic "currant jelly stools" are not typical of volvulus, and the pain is usually constant, not intermittent. *Necrotizing Enterocolitis* - NEC primarily affects **premature infants** and presents with abdominal distension, feeding intolerance, and bloody stools (often non-currant jelly). - The infant's age (6 months) makes NEC less likely, and the sudden, intermittent pain pattern is not typical. *Hirschsprung Disease* - Hirschsprung disease typically presents with **constipation** from birth, **abdominal distention**, and failure to pass meconium, rather than acute severe intermittent pain. - While it can lead to enterocolitis with bloody stools, the specific "currant jelly stool" appearance and the acute, intermittent nature of the symptoms are not characteristic.

Q: A 5-month-old infant presents with vomiting, diarrhea, and signs of dehydration. On examination, the infant has a sunken fontanelle and poor skin turgor. What is the next best step in management?

Oral rehydration solution. ***Oral rehydration solution*** - The presence of a **sunken fontanelle** and **poor skin turgor** indicates **some dehydration (moderate dehydration)** according to WHO classification. - **Oral rehydration solution (ORS)** is the **first-line treatment** for moderate dehydration as per WHO and IAP guidelines (Plan B therapy). - ORS should be given at **75 ml/kg over 4 hours** with close monitoring for improvement or deterioration. - ORS is effective, safe, and preferred over IV therapy when the child can drink and does not have severe dehydration or shock. *Intravenous fluids* - IV fluids are indicated for **severe dehydration** (lethargy, shock, inability to drink, unconsciousness) or **failure of ORS therapy**. - The clinical signs described (sunken fontanelle, poor skin turgor) without mention of shock, lethargy, or inability to drink suggest moderate, not severe dehydration. - Jumping directly to IV fluids bypasses the safer, equally effective, and less invasive ORS therapy. *Antibiotics* - Antibiotics are not indicated unless there is evidence of a **bacterial infection** such as bloody diarrhea or positive stool culture. - Most cases of acute diarrhea in infants are **viral** (rotavirus, norovirus) and self-limiting. - Routine antibiotic use may lead to resistance and disrupt normal gut flora. *Antidiarrheal medications* - **Antidiarrheal medications are contraindicated in infants** as per WHO and AAP guidelines. - They can prolong infection by preventing pathogen clearance and may cause serious complications like **ileus** or **toxic megacolon**. - Treatment focuses on rehydration, not stopping diarrhea.

Q: A 6-month-old infant presents with projectile vomiting and a palpable olive-shaped mass in the abdomen. What is the most likely diagnosis?

Pyloric stenosis. ***Pyloric stenosis*** - The classic presentation of **projectile vomiting** and a **palpable olive-shaped mass** in an infant is highly characteristic of pyloric stenosis. - This condition involves **hypertrophy of the pyloric muscle**, obstructing gastric outflow. *Gastroesophageal reflux disease* - While common in infants, **GERD** typically presents with spitting up or non-projectile vomiting and does not cause a palpable abdominal mass. - Vomiting in GERD is usually effortless and not forceful as described. *Intussusception* - **Intussusception** presents with intermittent abdominal pain, **currant jelly stools**, and sometimes a sausage-shaped mass, not an olive-shaped mass, and the vomiting is typically bilious, not projectile. - It usually occurs at a slightly older age than pyloric stenosis, often between 6 months and 3 years. *Hirschsprung disease* - **Hirschsprung disease** is characterized by **constipation** and abdominal distension, often presenting with delayed passage of meconium. - Vomiting, if present, is typically bilious or feculent, and there is no palpable olive-shaped mass associated with this condition.

Q: A previously healthy 4-year-old boy presents with sudden onset of abdominal pain and bloody diarrhea after recently returning from a camping trip. What is the most likely diagnosis?

Infectious gastroenteritis. ***Infectious gastroenteritis*** - The combination of **sudden onset bloody diarrhea** and **abdominal pain** following a **camping trip** strongly suggests bacterial gastroenteritis from contaminated food or water. - Common bacterial pathogens include **E. coli O157:H7** (from undercooked meat or contaminated water), **Shigella**, **Salmonella**, and **Campylobacter**. - The epidemiological context (camping) and clinical presentation (acute bloody diarrhea) make this the most likely diagnosis. *Appendicitis* - While appendicitis causes **abdominal pain**, it typically presents with **periumbilical pain** migrating to the right lower quadrant, **fever**, and **anorexia**. - Appendicitis does **not** present with profuse bloody diarrhea as a primary symptom. - The camping trip exposure and diarrhea-predominant presentation make infectious gastroenteritis more likely. *Hemolytic uremic syndrome* - HUS is a **complication** that can develop following infection with **E. coli O157:H7**, characterized by the triad of **thrombocytopenia**, **microangiopathic hemolytic anemia**, and **acute kidney injury**. - While bloody diarrhea is often the **initial prodrome**, HUS represents the subsequent systemic complication, not the acute gastrointestinal illness itself. - The question asks for the most likely diagnosis at this presentation, which is the infectious gastroenteritis, not yet HUS. *Intussusception* - Intussusception typically presents with **intermittent, colicky abdominal pain** (cyclical pattern every 15-20 minutes) and **'currant jelly' stool** (blood mixed with mucus). - Classic age group is **6 months to 3 years**, and patients often appear lethargic between pain episodes. - The **camping trip exposure**, **continuous bloody diarrhea** (rather than intermittent currant jelly stool), and age make infectious gastroenteritis more likely.

Question 1

A 6-week-old infant presents with projectile, non-bilious vomiting after feeds and poor weight gain. On examination, the infant appears eager to feed and has visible gastric peristalsis. What is the most likely diagnosis?

Accepted Answer

Pyloric stenosis

Answer

Intussusception

Answer

Hirschsprung disease

Answer

Necrotizing enterocolitis

Question 2

A 6-month-old infant presents with failure to thrive and chronic diarrhea. Examination reveals a distended abdomen. Which condition is most likely?

Accepted Answer

Cystic fibrosis

Answer

Celiac disease

Answer

Lactose intolerance

Answer

GERD

Question 3

A 7-year-old boy presents with recurrent episodes of abdominal pain, diarrhea, and failure to thrive. Laboratory findings show anti-tissue transglutaminase antibodies. What is the most likely diagnosis?

Accepted Answer

Celiac disease

Answer

Crohn's disease

Answer

Ulcerative colitis

Answer

Lactose intolerance

Question 4

A 3-year-old child is brought to the clinic with a history of constipation, abdominal pain, and irritability. Physical examination reveals a palpable abdominal mass. What is the most appropriate next step in management?

Accepted Answer

Abdominal ultrasound

Answer

Barium enema

Answer

Stool softeners

Answer

CT scan of the abdomen

Question 5

A young child presents with a palpable mass in the lower right quadrant. Imaging confirms intussusception. Which part of the intestine most commonly acts as the intussusceptum (telescoping segment)?

Accepted Answer

Ileum

Answer

Duodenum

Answer

Jejunum

Answer

Colon

Question 6

A 6-year-old boy presents with fever, abdominal pain, and a palpable mass in the left lower quadrant. An abdominal ultrasound reveals intussusception. What is the most appropriate initial management?

Accepted Answer

Intravenous fluids

Answer

Pneumatic (air) enema reduction under fluoroscopic guidance

Answer

Surgical intervention

Answer

Observation

Question 7

A 6-month-old infant presents with recurrent episodes of sudden-onset crying, drawing up of the legs, and currant jelly stools. What is the most likely diagnosis?

Accepted Answer

Intussusception

Answer

Volvulus

Answer

Necrotizing Enterocolitis

Answer

Hirschsprung Disease

Question 8

A 5-month-old infant presents with vomiting, diarrhea, and signs of dehydration. On examination, the infant has a sunken fontanelle and poor skin turgor. What is the next best step in management?

Accepted Answer

Oral rehydration solution

Answer

Intravenous fluids

Answer

Antibiotics

Answer

Antidiarrheal medications

Question 9

A 6-month-old infant presents with projectile vomiting and a palpable olive-shaped mass in the abdomen. What is the most likely diagnosis?

Accepted Answer

Pyloric stenosis

Answer

Gastroesophageal reflux disease

Answer

Intussusception

Answer

Hirschsprung disease

Question 10

A previously healthy 4-year-old boy presents with sudden onset of abdominal pain and bloody diarrhea after recently returning from a camping trip. What is the most likely diagnosis?

Accepted Answer

Infectious gastroenteritis

Answer

Appendicitis

Answer

Hemolytic uremic syndrome

Answer

Intussusception

Gastroenterology — MCQs

Gastroenterology — MCQs

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