Dietary sources and requirements US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Dietary sources and requirements. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Dietary sources and requirements US Medical PG Question 1: A 26-year-old man from India visits the clinic with complaints of feeling tired all the time and experiencing lack of energy for the past couple of weeks. He also complains of weakness and numbness of his lower limbs. He has been strictly vegan since the age of 18, including not consuming eggs and milk. He does not take any vitamin or dietary supplements. Physical examination reveals a smooth, red beefy tongue along with lower extremity sensory and motor deficits. What other finding is most likely to accompany this patient’s condition?
- A. Upper limb weakness
- B. Psychiatric symptoms
- C. Decreased visual acuity
- D. Microcytic anemia
- E. Ataxia (Correct Answer)
Dietary sources and requirements Explanation: **Ataxia**
- The patient's history of being a strict vegan, fatigue, weakness, numbness, and neurological deficits (sensory and motor) along with a **smooth, red beefy tongue** are classic signs of **vitamin B12 deficiency**.
- **Vitamin B12 deficiency** often leads to **subacute combined degeneration of the spinal cord**, which can manifest as **ataxia**, spasticity, and paresthesias due to demyelination.
*Upper limb weakness*
- While B12 deficiency can cause generalized weakness, the question specifically highlights **lower extremity sensory and motor deficits**, with **ataxia** being a more characteristic and often earlier neurological sign of spinal cord involvement than upper limb weakness.
- Upper limb weakness might develop in advanced stages, but it is not the **most likely** accompanying finding in the early or moderate stages often described with lower limb involvement and ataxia.
*Psychiatric symptoms*
- **Psychiatric symptoms** such as depression, irritability, and cognitive impairment can occur in **vitamin B12 deficiency**, but **ataxia** is a more direct and common neurological consequence stemming from the demyelination in the spinal cord.
- While possible, the question asks for the **most likely** additional finding given the specific neurological presentation.
*Decreased visual acuity*
- **Optic neuropathy** and **decreased visual acuity** can occur in some cases of **vitamin B12 deficiency**, but it is less common than the spinal cord and peripheral nerve manifestations like ataxia and paresthesias.
- The presented symptoms directly point to spinal cord involvement, making **ataxia** a more prominent associated neurological finding.
*Microcytic anemia*
- **Vitamin B12 deficiency** typically causes **megaloblastic (macrocytic) anemia**, not microcytic anemia.
- **Microcytic anemia** is primarily associated with **iron deficiency**, lead poisoning, or thalassemia.
Dietary sources and requirements US Medical PG Question 2: A 29-year-old woman came to the emergency department due to severe symptoms of intoxication and unexplained convulsions. She is accompanied by her husband who reports that she takes disulfiram. There is no prior personal and family history of epilepsy. She shows signs of confusion, hyperirritability, and disorientation. On further evaluation, the patient is noted to have stomatitis, glossitis, and cheilosis. A chest X-ray is unremarkable. The deficiency of which of the vitamins below is likely to be the major cause of this patient’s symptoms?
- A. B12
- B. B6 (Correct Answer)
- C. B9
- D. B2
- E. B3
Dietary sources and requirements Explanation: ***B6***
- The patient's presentation of **seizures, confusion, and oral symptoms (stomatitis, glossitis, cheilosis)** in the context of **disulfiram use** strongly suggests **pyridoxine (vitamin B6) deficiency**.
- **Disulfiram inhibits pyridoxine phosphokinase**, which converts pyridoxine to its active form (pyridoxal-5-phosphate), leading to functional B6 deficiency.
- **Seizures are a hallmark of B6 deficiency** because pyridoxal-5-phosphate is a cofactor for glutamic acid decarboxylase, which synthesizes GABA; reduced GABA leads to increased neuronal excitability and seizures.
- B6 deficiency also causes **peripheral neuropathy, cheilosis, glossitis, and stomatitis**.
*B2*
- Vitamin B2 (riboflavin) deficiency does cause **stomatitis, glossitis, and cheilosis**, along with seborrheic dermatitis and normocytic anemia.
- However, **riboflavin deficiency does not typically cause seizures**, which is the most acute and concerning symptom in this case.
- While disulfiram can affect multiple vitamin pathways, the seizure presentation points specifically to B6.
*B12*
- Vitamin B12 deficiency typically presents with **megaloblastic anemia** and **neurological symptoms** such as subacute combined degeneration (posterior column and corticospinal tract), peripheral neuropathy, and cognitive changes.
- The acute seizures and oral mucosal symptoms are not characteristic of B12 deficiency.
*B9*
- Vitamin B9 (folate) deficiency primarily causes **megaloblastic anemia** with symptoms of fatigue and weakness.
- While **glossitis** can occur, it's usually accompanied by anemia, and seizures are not a feature of folate deficiency.
- The clinical picture does not fit folate deficiency.
*B3*
- Vitamin B3 (niacin) deficiency causes **pellagra**, characterized by the classic triad: **dermatitis, diarrhea, and dementia** (the "3 Ds").
- While glossitis can be present, the **absence of photosensitive dermatitis and diarrhea** makes pellagra unlikely.
- Seizures are not a typical feature of pellagra.
Dietary sources and requirements US Medical PG Question 3: A 37-year-old man with Crohn disease is admitted to the hospital because of acute small bowel obstruction. Endoscopy shows a stricture in the terminal ileum. The ileum is surgically resected after endoscopic balloon dilatation fails to relieve the obstruction. Three years later, he returns for a follow-up examination. He takes no medications. This patient is most likely to have which of the following physical exam findings?
- A. Dry skin and keratomalacia
- B. Weakness and ataxia (Correct Answer)
- C. Hyperreflexia with tetany
- D. Gingival swelling and bleeding
- E. Pallor with koilonychia
Dietary sources and requirements Explanation: ***Weakness and ataxia***
- This patient with a history of **Crohn disease** and significant **ileal resection** is at high risk for **vitamin B12 deficiency** due to the removal of the primary site of absorption in the terminal ileum.
- **Vitamin B12 deficiency** can lead to subacute combined degeneration of the spinal cord, manifesting as **weakness**, **ataxia**, and **paresthesias**.
*Dry skin and keratomalacia*
- This presentation is indicative of **vitamin A deficiency**, which can occur in malabsorption but is less specific to ileal resection than B12 deficiency.
- While fat-soluble vitamins (A, D, E, K) are absorbed in the small intestine, severe isolated vitamin A deficiency causing keratomalacia is not the most likely primary finding after ileal resection.
*Hyperreflexia with tetany*
- These symptoms typically suggest **hypocalcemia** or **hypomagnesemia**, often due to vitamin D deficiency or malabsorption of minerals.
- Although possible with generalized malabsorption, it is not the most characteristic neurological complication following isolated ileal resection compared to vitamin B12 deficiency.
*Gingival swelling and bleeding*
- This is a hallmark of **scurvy**, caused by **vitamin C deficiency**, which is typically absorbed in the small intestine and does not correlate specifically with ileal resection.
- This would be a less likely complication given the specific history compared to micronutrient deficiencies related to terminal ileum function.
*Pallor with koilonychia*
- **Pallor** and **koilonychia (spoon nails)** are characteristic signs of **iron deficiency anemia**.
- While iron is absorbed in the duodenum and proximal jejunum, and anemia is common in Crohn disease, the specific neurological symptoms from B12 deficiency are generally more prominent after ileal resection.
Dietary sources and requirements US Medical PG Question 4: A 51-year-old gentleman presents with new onset bilateral paresthesias of his feet. He also admits that he has not been able to exercise as much as previously and his friends have commented that he looks pale. Upon physical exam you find that he has conjunctival pallor and mildly decreased sensation and proprioception on his feet bilaterally. Based on your suspicions you decide to obtain a blood smear where you see megaloblasts as well as hypersegmented neutrophils. Given these findings you decide to investigate the cause of his disorder by injecting an intramuscular vitamin, then feeding him a radiolabeled version of the same vitamin orally. After waiting 24 hours you see that no radiolabeled vitamin appears in the urine so you repeat the test with intrinsic factor added to the oral mixture, at which point 20% of the radiolabeled vitamin appears in the urine. Which of the following is the most likely etiology of this gentleman's symptoms?
- A. Bacterial overgrowth
- B. Pancreatic insufficiency
- C. Insufficient vitamin intake
- D. Pernicious anemia (Correct Answer)
- E. Folate deficiency
Dietary sources and requirements Explanation: ***Pernicious anemia***
- The combination of **neurological symptoms** (paresthesias, decreased proprioception), **anemia symptoms** (pallor, fatigue), **megaloblastic anemia** on blood smear (megaloblasts, hypersegmented neutrophils), and the specific Schilling test results (vitamin B12 malabsorption corrected by added **intrinsic factor**) is diagnostic for pernicious anemia.
- Pernicious anemia is an autoimmune condition targeting **gastric parietal cells** or **intrinsic factor** itself, leading to **vitamin B12 deficiency** due to impaired absorption.
*Bacterial overgrowth*
- **Bacterial overgrowth in the small intestine** can consume vitamin B12, leading to deficiency, but the Schilling test would show improvement with **antibiotics**, not intrinsic factor.
- While it can cause B12 deficiency and megaloblastic anemia, improvement upon adding intrinsic factor points away from this diagnosis.
*Pancreatic insufficiency*
- **Pancreatic enzymes** are required to cleave vitamin B12 from its binding proteins, but the **Schilling test** would show improvement with **pancreatic enzyme supplements**, not intrinsic factor.
- While pancreatic insufficiency can lead to B12 malabsorption, the specific Schillings test results rule it out.
*Insufficient vitamin intake*
- **Insufficient dietary intake** of vitamin B12 would lead to B12 deficiency, but in such a case, the **Schilling test** would show normal absorption of radiolabeled B12 even without intrinsic factor in the second stage.
- The initial B12 malabsorption indicates an absorption problem, not solely a dietary lack.
*Folate deficiency*
- **Folate deficiency** also causes **megaloblastic anemia** and can present with fatigue and pallor, but it does **not cause neurological symptoms** like paresthesias or proprioception deficits.
- The Schilling test specifically evaluates **vitamin B12 absorption**, not folate levels, so it would be irrelevant for diagnosing pure folate deficiency.
Dietary sources and requirements US Medical PG Question 5: A 19-year-old woman with a known history of malabsorption presents with a painful red tongue, red eyes, and cracked lips. She says her symptoms gradually began 4 months ago after moving away from home for college. She also complains of photophobia, spontaneous lacrimation, and itchy dermatitis. Past medical history is significant for a long-standing malabsorption syndrome, which she says that she hasn't been able to maintain her normal diet or take her vitamins regularly due to her busy schedule. The patient is afebrile and vital signs are within normal limits. On physical examination, she has a malnourished appearance with significant pallor. Conjunctival injection is present bilaterally. Which of the following diagnostic tests will be most helpful to support the diagnosis of the most likely vitamin deficiency in this patient?
- A. Measurement of erythrocyte folate levels
- B. Measurement of erythrocyte glutathione reductase activity (Correct Answer)
- C. Measurement of erythrocyte glutamic oxaloacetic transaminase activity
- D. Measurement of erythrocyte transketolase activity
- E. Measurement of serum methylmalonic acid levels
Dietary sources and requirements Explanation: ***Measurement of erythrocyte glutathione reductase activity***
- This measures the activity of an enzyme that requires **flavin adenine dinucleotide (FAD)**, a coenzyme derived from **riboflavin (vitamin B2)**. Reduced activity, especially after FAD stimulation, suggests **riboflavin deficiency**.
- The patient's symptoms (painful red tongue, red eyes, cracked lips, photophobia, spontaneous lacrimation, itchy dermatitis) are classic manifestations of **ariboflavinosis**, exacerbated by her history of malabsorption and poor dietary intake.
*Measurement of erythrocyte folate levels*
- This test is used to diagnose **folate (vitamin B9) deficiency**, which can cause **macrocytic anemia** and megaloblastic changes.
- While malabsorption can lead to folate deficiency, the patient's specific constellation of symptoms (cheilosis, glossitis, angular stomatitis, ocular symptoms) is more indicative of **riboflavin deficiency**, not folate.
*Measurement of erythrocyte glutamic oxaloacetic transaminase activity*
- This (also known as AST or Aspartate Aminotransferase) enzyme requires **pyridoxal phosphate (vitamin B6)** as a coenzyme. Measurement of its activity, particularly with and without B6 supplementation, can assess **vitamin B6 status**.
- While B6 deficiency can present with dermatitis and glossitis, the prominent ocular symptoms and cheilosis point more strongly towards **riboflavin deficiency**.
*Measurement of erythrocyte transketolase activity*
- This test assesses **thiamine (vitamin B1) status**, as transketolase requires **thiamine pyrophosphate (TPP)** as a cofactor. Reduced activity, especially after TPP stimulation, indicates **thiamine deficiency (beri-beri)**.
- Thiamine deficiency typically presents with neurological symptoms (dry beri-beri) or cardiovascular symptoms (wet beri-beri), which are not described in this patient's presentation.
*Measurement of serum methylmalonic acid levels*
- Elevated **methylmalonic acid (MMA)** levels in serum are a highly sensitive and specific indicator of **vitamin B12 deficiency**, as B12 is essential for the conversion of MMA to succinyl CoA.
- While vitamin B12 deficiency can cause glossitis and neurological symptoms, the patient's specific ocular and dermatological findings are not characteristic of B12 deficiency.
Dietary sources and requirements US Medical PG Question 6: A homeless woman presents with shortness of breath on exertion and pedal edema. Cardiac workup performed shows evidence of dilated cardiomyopathy and increased cardiac output. She also has decreased sensation over both extremities bilaterally. Which vitamin deficiency most likely caused these symptoms?
- A. Vitamin B6
- B. Vitamin C
- C. Vitamin B1 (Correct Answer)
- D. Vitamin B3
- E. Vitamin A
Dietary sources and requirements Explanation: ***Vitamin B1***
- The combination of **dilated cardiomyopathy**, **high-output heart failure** (manifesting as shortness of breath and pedal edema), and **peripheral neuropathy** (decreased sensation) is classic for **wet beriberi**, caused by thiamine (Vitamin B1) deficiency.
- **Homelessness** is a significant risk factor for nutritional deficiencies, including thiamine deficiency, due to inadequate diet.
*Vitamin B6*
- Deficiency can cause **peripheral neuropathy**, but it does not typically lead to **dilated cardiomyopathy** or **high-output heart failure**.
- Other manifestations of B6 deficiency include **sideroblastic anemia** and **seizures**.
*Vitamin C*
- Deficiency causes **scurvy**, characterized by **gingivitis**, **poor wound healing**, **petechiae**, and joint pain.
- It does not present with **cardiomyopathy** or **neuropathy** as described.
*Vitamin B3*
- Deficiency causes **pellagra**, characterized by the "3 Ds": **dermatitis**, **diarrhea**, and **dementia**.
- While it can affect the nervous system (dementia), it does not typically cause **dilated cardiomyopathy** or **peripheral neuropathy**.
*Vitamin A*
- Deficiency primarily affects **vision** (e.g., **night blindness**, **xerophthalmia**) and immune function.
- It is not associated with **cardiac** or **neurological symptoms** like those described in the patient.
Dietary sources and requirements US Medical PG Question 7: A 4-year-old girl is brought to the physician for a routine checkup. She was recently adopted and has never seen a doctor before. The patient's parents state she was very emaciated when they adopted her and noticed she has trouble seeing in the evening. They also noted that she was experiencing profuse foul-smelling diarrhea as well, which is currently being worked up by a gastroenterologist. Her temperature is 97.8°F (36.6°C), blood pressure is 104/54 mmHg, pulse is 100/min, respirations are 19/min, and oxygen saturation is 98% on room air. The girl appears very thin. She has dry skin noted on physical exam. Laboratory studies are ordered as seen below.
Hemoglobin: 12 g/dL
Hematocrit: 36%
Leukocyte count: 4,500/mm^3 with normal differential
Platelet count: 191,000/mm^3
Serum:
Na+: 139 mEq/L
Cl-: 100 mEq/L
K+: 3.8 mEq/L
HCO3-: 28 mEq/L
BUN: 20 mg/dL
Glucose: 88 mg/dL
Creatinine: 0.7 mg/dL
Ca2+: 9.0 mg/dL
Which of the following findings is also likely to be seen in this patient?
- A. Xerophthalmia (Correct Answer)
- B. Cheilosis
- C. Ataxia
- D. Perifollicular hemorrhages
- E. Diarrhea
Dietary sources and requirements Explanation: **Xerophthalmia**
- The patient's history of **malnutrition** and **night blindness** strongly suggests **vitamin A deficiency**, which can lead to **xerophthalmia** (dry eyes and corneal damage).
- Her **foul-smelling diarrhea** indicates **fat malabsorption**, which impairs the absorption of fat-soluble vitamins, including **vitamin A**.
*Cheilosis*
- **Cheilosis** (cracking at the corners of the mouth) is primarily a symptom of **riboflavin (vitamin B2)** or **pyridoxine (vitamin B6)** deficiency.
- While the patient is malnourished, the specific symptoms point more directly to a fat-soluble vitamin deficiency.
*Ataxia*
- **Ataxia** (lack of voluntary coordination of muscle movements) is a neurological symptom associated with **vitamin B12** or **vitamin E deficiency**.
- While possible in severe malnutrition, it is not directly linked to the presented symptoms of night blindness and dry skin.
*Perifollicular hemorrhages*
- **Perifollicular hemorrhages** (small bruising especially around hair follicles) are characteristic of **scurvy**, caused by severe **vitamin C deficiency**.
- The patient's symptoms do not align with scurvy, which typically presents with bleeding gums, poor wound healing, and joint pain.
*Diarrhea*
- The patient is already described as experiencing **profuse foul-smelling diarrhea**, which is being worked up by a gastroenterologist.
- The question asks for an additional finding likely to be seen, not a symptom already present.
Dietary sources and requirements US Medical PG Question 8: A 3-year-old boy is brought to the physician for a follow-up examination. He has lactose intolerance. His family emigrated from Somalia 6 months ago. He is at the 30th percentile for height and 15th percentile for weight. Vital signs are within normal limits. Examination shows pale conjunctivae, an erythematous throat, and swollen tongue. There is inflammation of the perioral and labial mucosa, and peeling and cracking of the skin at the corners of the mouth. Cardiopulmonary examination shows no abnormalities. His hemoglobin concentration is 9.8 g/dL and mean corpuscular volume is 87 μm3. If left untreated, this child is also most likely to develop which of the following?
- A. Dilated cardiomyopathy
- B. Keratomalacia
- C. Ataxia
- D. Corneal vascularization (Correct Answer)
- E. Hypersegmented neutrophils
Dietary sources and requirements Explanation: ***Corneal vascularization***
- The clinical presentation of **angular cheilitis** (cracking/peeling at mouth corners), **glossitis** (swollen, erythematous tongue), **perioral and labial inflammation**, and **normocytic anemia** in a child with **lactose intolerance** (limiting dairy intake) strongly suggests **riboflavin (vitamin B2) deficiency**.
- If left untreated, riboflavin deficiency progresses to **corneal vascularization**, characterized by blood vessel invasion into the normally avascular cornea, often accompanied by photophobia and conjunctival injection.
- **Dairy products are the primary dietary source of riboflavin**, making lactose-intolerant individuals particularly vulnerable to deficiency.
*Hypersegmented neutrophils*
- This is the hallmark hematologic finding in **megaloblastic anemia** caused by **folate or vitamin B12 deficiency**.
- These deficiencies cause **macrocytic anemia** (MCV >100 μm³), but this patient has **normocytic anemia** (MCV 87 μm³), ruling out megaloblastic causes.
- The normal MCV excludes folate/B12 deficiency as the primary diagnosis.
*Dilated cardiomyopathy*
- This is the classic cardiac manifestation of **thiamine (vitamin B1) deficiency** (wet beriberi).
- While severe malnutrition can affect cardiac function, the specific clinical features presented (angular cheilitis, glossitis) are not characteristic of thiamine deficiency.
- Thiamine deficiency typically presents with peripheral neuropathy, muscle weakness, and cardiovascular collapse, not the oral/mucosal lesions seen here.
*Keratomalacia*
- This condition results from **severe vitamin A deficiency** and involves corneal softening, ulceration, and blindness.
- Vitamin A deficiency presents with **night blindness, xerophthalmia, and Bitot's spots**, not the oral mucosal lesions described.
- The clinical picture does not support vitamin A deficiency.
*Ataxia*
- **Ataxia** is associated with **vitamin B12 deficiency** (subacute combined degeneration affecting posterior columns and corticospinal tracts) or **vitamin E deficiency**.
- Again, the **normal MCV** rules out B12 deficiency as the primary diagnosis.
- The prominent oral and skin findings are not typical of neurological vitamin deficiencies.
Dietary sources and requirements US Medical PG Question 9: An investigator is studying nutritional deficiencies in humans. A group of healthy volunteers are started on a diet deficient in pantothenic acid. After 4 weeks, several of the volunteers develop irritability, abdominal cramps, and burning paresthesias of their feet. These symptoms are fully reversed after reintroduction of pantothenic acid to their diet. The function of which of the following enzymes was most likely impaired in the volunteers during the study?
- A. Gamma-glutamyl carboxylase
- B. Alpha-ketoglutarate dehydrogenase (Correct Answer)
- C. Dopamine beta-hydroxylase
- D. Methionine synthase
- E. Glutathione reductase
Dietary sources and requirements Explanation: ***Alpha-ketoglutarate dehydrogenase***
- **Pantothenic acid** (vitamin B5) is a precursor of **coenzyme A (CoA)**, which is essential for the function of alpha-ketoglutarate dehydrogenase in the **Krebs cycle**.
- Impairment of this enzyme, critical for energy production, can lead to widespread metabolic dysfunction, manifesting as neurological and gastrointestinal symptoms like **irritability, abdominal cramps**, and **burning paresthesias**, which are classic signs of pantothenic acid deficiency.
*Gamma-glutamyl carboxylase*
- This enzyme is involved in the post-translational modification of several proteins, including **clotting factors**, and requires **vitamin K** as a cofactor.
- Its deficiency leads to bleeding disorders, not the neurological and GI symptoms described.
*Dopamine beta-hydroxylase*
- This enzyme converts **dopamine to norepinephrine** and requires vitamin C and copper.
- Its impairment can affect neurotransmitter synthesis but is not directly linked to pantothenic acid deficiency.
*Methionine synthase*
- This enzyme is crucial for the metabolism of **homocysteine** and requires **vitamin B12** and **folate** as cofactors.
- Its deficiency is associated with megaloblastic anemia and neurological symptoms, but not the specific presentation seen with pantothenic acid deficiency.
*Glutathione reductase*
- This enzyme is essential for maintaining the reduced state of **glutathione**, an antioxidant, and requires **riboflavin** (vitamin B2) in its coenzyme form, FAD.
- Dysfunction typically leads to oxidative stress, hemolytic anemia, and other symptoms different from those described.
Dietary sources and requirements US Medical PG Question 10: A 34-year-old woman with Crohn disease comes to the physician because of a 4-week history of nausea, bloating, and epigastric pain that occurs after meals and radiates to the right shoulder. Four months ago, she underwent ileocecal resection for an acute intestinal obstruction. An ultrasound of the abdomen shows multiple echogenic foci with acoustic shadows in the gallbladder. Which of the following mechanisms most likely contributed to this patient’s current presentation?
- A. Decreased biliary concentration of bile acids (Correct Answer)
- B. Increased hepatic cholesterol secretion
- C. Decreased fat absorption
- D. Increased bilirubin production
- E. Decreased motility of the gallbladder
Dietary sources and requirements Explanation: ***Decreased biliary concentration of bile acids***
- The patient's **Crohn disease** and recent **ileocecal resection** impair the reabsorption of bile acids in the terminal ileum, leading to reduced bile acid concentration in the enterohepatic circulation.
- This **reduced bile acid pool** causes supersaturation of cholesterol in bile, leading to the formation of **cholesterol gallstones**, consistent with the ultrasound findings of echogenic foci with acoustic shadows.
*Increased hepatic cholesterol secretion*
- While increased hepatic cholesterol secretion can contribute to gallstone formation, the primary driver in this patient's case is the **impaired enterohepatic recirculation of bile acids** due to Crohn disease and ileocecal resection.
- The specific history points to a problem with bile acid reabsorption, not necessarily an isolated increase in cholesterol synthesis or secretion.
*Decreased fat absorption*
- Decreased fat absorption (malabsorption) can occur in Crohn disease due to inflammation or resection, but it primarily leads to **steatorrhea** and **fat-soluble vitamin deficiencies**.
- While malabsorption of fat can indirectly impact bile acid metabolism, the more direct and relevant mechanism for gallstone formation here is the **disruption of bile acid reabsorption** in the ileum.
*Increased bilirubin production*
- Increased bilirubin production primarily leads to **pigment gallstones** (black or brown stones), which are more commonly associated with conditions causing hemolysis or biliary infections.
- The ultrasound findings of **echogenic foci with acoustic shadows** are characteristic of **cholesterol gallstones**, not bilirubin stones.
*Decreased motility of the gallbladder*
- Poor gallbladder motility (stasis) can contribute to gallstone formation, as it allows bile to become more concentrated and cholesterol to precipitate.
- However, in the context of Crohn disease and ileocecal resection, the most significant and *primary* mechanism for gallstone development is the **disruption of bile acid enterohepatic circulation**, rather than primarily gallbladder dysmotility.
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