Reviewer GI Flashcards
A 28-year-old pregnant woman at 20 weeks gestation presents to the emergency department with sudden-onset nausea, profuse vomiting, and abdominal cramping. She attended a wedding reception 3 hours ago where she consumed cream-filled pastries and potato salad. She denies fever or bloody stools. Her vitals are stable, and physical examination is unremarkable.
What is the most likely causative agent?
A. Clostridium perfringens
B. Bacillus cereus
C. Staphylococcus aureus
D. Enterotoxigenic Escherichia coli
C. Staphylococcus aureus
📌 Key point: Preformed enterotoxin; short incubation (1-6 hours); profuse vomiting is the hallmark. No fever, self-limiting.
A 32-year-old pregnant woman at 16 weeks gestation presents with profuse watery diarrhea 10 hours after eating at a buffet. She had beef stew, rice, and salad. She reports mild abdominal cramps but denies fever or vomiting. Her symptoms resolve within 24 hours with oral hydration.
Which of the following is the best treatment?
A. Ciprofloxacin
B. Metronidazole
C. IV fluids and antibiotics
D. Supportive care with oral rehydration
D. Supportive care with oral rehydration
📌 Key point: Clostridium perfringens produces enterotoxin from contaminated meat dishes. Incubation 8-16 hours, watery diarrhea without vomiting, resolves within 24 hours.
A 30-year-old woman, 18 weeks pregnant, returns from a trip to Mexico and presents with profuse watery diarrhea for the past 2 days. She has mild abdominal cramps but denies fever or vomiting. She is slightly dehydrated, but vitals are stable.
Which of the following is the most appropriate treatment?
A. Supportive care only
B. Ciprofloxacin
C. Metronidazole
D. Azithromycin
B. Ciprofloxacin
📌 Key point: ETEC causes Traveler’s Diarrhea with watery stools, no fever. Ciprofloxacin is the first-line treatment (azithromycin for pregnancy).
A 26-year-old pregnant woman at 24 weeks gestation presents with severe vomiting within 3 hours after eating fried rice at an Asian restaurant. She denies fever or diarrhea.
What is the most likely cause of her symptoms?
A. Clostridium perfringens
B. Bacillus cereus
C. Vibrio cholerae
D. Norovirus
B. Bacillus cereus
📌 Key point: Short incubation (1-6 hours), vomiting prominent, often from fried rice (preformed toxin). Diarrheal form has longer incubation (~8-16 hours).
A 35-year-old pregnant woman at 30 weeks gestation presents with watery diarrhea 12 hours after eating leftover chicken. She denies vomiting but has mild abdominal cramping. No fever or bloody stools are noted.
Which of the following statements is true?
A. Antibiotics are required to shorten the duration of illness.
B. This infection is likely caused by a toxin-producing organism.
C. The patient should be admitted for IV antibiotics due to pregnancy.
D. Stool cultures should be sent immediately for pathogen identification.
B. This infection is likely caused by a toxin-producing organism.
📌 Key point: Most foodborne toxin-mediated diarrheas (e.g., C. perfringens, B. cereus, ETEC) do not require antibiotics and are self-limiting.
A 30-year-old pregnant woman at 22 weeks gestation returns from a vacation in Thailand. She presents with watery diarrhea, mild abdominal cramps, and fatigue for the past 3 days. She denies blood in stools and has no significant vomiting or fever.
Which of the following is the most likely causative agent?
A. Giardia lamblia
B. Enteroadherent Escherichia coli
C. Norovirus
D. Vibrio cholerae
B. Enteroadherent Escherichia coli
📌 Key point: Traveler’s diarrhea (ETEC or EAEC) is the most common cause of watery diarrhea without significant fever or vomiting. Ciprofloxacin is the first-line treatment, but azithromycin is preferred in pregnancy.
A 28-year-old pregnant woman at 18 weeks gestation presents with greasy, foul-smelling stools, bloating, and intermittent diarrhea for the past 7 days. She recently returned from a camping trip where she drank from a stream. She denies fever or vomiting.
What is the best treatment?
A. Ciprofloxacin
B. Metronidazole
C. Tinidazole
D. Albendazole
C. Tinidazole
📌 Key point: Giardia spp. causes prolonged, fatty diarrhea and is linked to contaminated water. Tinidazole is the first-line treatment, but Metronidazole is used in pregnancy.
A 35-year-old pregnant woman at 24 weeks presents with mild watery diarrhea, weight loss, bloating, and perianal itching at night. She has no fever or vomiting. Stool examination reveals ova and parasites.
Which of the following is the most appropriate treatment?
A. Ciprofloxacin
B. Tinidazole
C. Albendazole
D. Azithromycin
C. Albendazole
📌 Key point: Helminths (e.g., Enterobius, Ascaris, Strongyloides) cause chronic symptoms. Albendazole is the treatment of choice but contraindicated in the first trimester.
A 32-year-old pregnant woman at 30 weeks gestation presents with intermittent diarrhea, bloating, and mild weight loss over the past 3 weeks. She recently returned from a mission trip in a rural area with poor sanitation. Stool microscopy reveals cysts and trophozoites.
Which of the following is the best next step?
A. Start Ciprofloxacin
B. Prescribe Metronidazole
C. Wait for self-resolution
D. Perform stool culture
B. Prescribe Metronidazole
📌 Key point: Chronic diarrhea, weight loss, and exposure to contaminated water suggest Giardiasis. Metronidazole is preferred in pregnancy, as Tinidazole is contraindicated.
A 29-year-old pregnant woman at 14 weeks presents with persistent watery diarrhea, mild bloating, and fatigue for 2 weeks after traveling to a developing country. She has no fever or vomiting. Stool culture is negative, but stool antigen testing is positive for a parasite.
What is the most likely pathogen?
A. Enteroaggregative E. coli
B. Giardia lamblia
C. Strongyloides stercoralis
D. Vibrio cholerae
B. Giardia lamblia
📌 Key point: Giardia causes prolonged watery diarrhea with bloating and is diagnosed by stool antigen testing. Treat with Metronidazole in pregnancy.
A 34-year-old pregnant woman at 24 weeks gestation presents with profuse watery diarrhea for the past 3 days, accompanied by low-grade fever and abdominal cramping. She was recently treated with clindamycin for a dental infection. Stool testing is positive for C. difficile toxin.
Which of the following is the best treatment?
A. Metronidazole
B. Oral Vancomycin
C. Ciprofloxacin
D. Supportive care only
B. Oral Vancomycin
📌 Key point: C. difficile infection occurs after recent antibiotic use and presents with watery diarrhea, fever, and leukocytosis. Oral Vancomycin is the first-line treatment, as Metronidazole is no longer recommended.
A 29-year-old pregnant woman at 28 weeks gestation presents with severe abdominal pain, bloody diarrhea, fever (38.5°C), and leukocytosis (WBC 20,000/mm³). She was treated with amoxicillin-clavulanate for a UTI two weeks ago. Abdominal imaging reveals toxic megacolon.
What is the next best step in management?
A. IV Metronidazole + Oral Vancomycin
B. Ciprofloxacin
C. Loperamide
D. Supportive care only
A. IV Metronidazole + Oral Vancomycin
📌 Key point: Severe C. difficile colitis (bloody diarrhea, toxic megacolon, high WBC) requires oral vancomycin + IV metronidazole. Loperamide is contraindicated as it may worsen colitis.
A 32-year-old pregnant woman at 30 weeks presents with bloody diarrhea and mild abdominal pain for 2 days. She recently ate an undercooked hamburger. She denies fever but is feeling weak. Laboratory results show Hgb 9.0 g/dL, platelets 110,000, and increased creatinine.
Which of the following is the most appropriate treatment?
A. Ciprofloxacin
B. Vancomycin
C. Supportive care only
D. Ceftriaxone
C. Supportive care only
📌 Key point: EHEC (Shiga toxin-producing E. coli) presents with bloody diarrhea without fever after consuming undercooked beef. Antibiotics are contraindicated due to the risk of hemolytic-uremic syndrome (HUS).
A 27-year-old pregnant woman at 26 weeks presents with bloody diarrhea, pallor, fatigue, and decreased urine output. Laboratory results reveal anemia, thrombocytopenia, and acute kidney injury. She ate undercooked meat 5 days ago.
What is the most appropriate management?
A. Start Ciprofloxacin
B. IV fluids and supportive care
C. Plasma exchange
D. Start broad-spectrum antibiotics
B. IV fluids and supportive care
📌 Key point: HUS is a complication of EHEC with microangiopathic hemolytic anemia, thrombocytopenia, and renal failure. Fluids and supportive care are first-line; antibiotics are avoided as they increase toxin release.
A 35-year-old pregnant woman presents with bloody diarrhea and low-grade fever. She was recently hospitalized for pneumonia and treated with ceftriaxone. Stool testing for C. difficile toxin is negative, and stool culture reveals E. coli O157:H7.
Which of the following best differentiates these two pathogens?
A. C. difficile is associated with foodborne outbreaks, while EHEC occurs post-antibiotic use.
B. C. difficile produces watery diarrhea, while EHEC causes bloody diarrhea.
C. EHEC requires immediate antibiotic treatment, while C. difficile does not.
D. Both require oral vancomycin for treatment.
B. C. difficile produces watery diarrhea, while EHEC causes bloody diarrhea.
📌 Key point: C. difficile → Watery diarrhea, post-antibiotics.
EHEC → Bloody diarrhea, undercooked beef, NO antibiotics.
A 30-year-old pregnant woman at 18 weeks presents with profuse watery diarrhea, vomiting, and high fever (39°C) for the past 2 days. She recently attended a family gathering where several children had similar symptoms. She denies blood in stools.
What is the most likely pathogen?
A. Clostridioides difficile
B. Norovirus
C. Rotavirus
D. Enterohemorrhagic E. coli
C. Rotavirus
📌 Key point: Rotavirus is a leading cause of severe watery diarrhea in children and adults, often spread in group settings (e.g., daycares, family gatherings). Fever, vomiting, and watery stools are hallmarks.
A 27-year-old pregnant woman at 20 weeks gestation presents with sudden-onset nausea, vomiting, watery diarrhea, and fever after returning from a cruise ship vacation. Several other passengers reported similar symptoms. Symptoms started 1 day after exposure and resolved within 48 hours.
What is the most likely cause?
A. Vibrio cholerae
B. Norovirus
C. Salmonella
D. Giardia lamblia
B. Norovirus
📌 Key point: Norovirus causes explosive outbreaks in cruise ships, schools, and healthcare facilities. Short incubation (12-48 hrs), vomiting + watery diarrhea. Self-limiting, supportive care only.
A 35-year-old pregnant woman at 32 weeks gestation presents with watery diarrhea, vomiting, and fever (38.8°C) for 3 days. She is dizzy on standing, has dry mucous membranes, and a pulse of 115 bpm.
What is the next best step in management?
A. Oral rehydration therapy (ORT)
B. Ciprofloxacin
C. IV fluids
D. Vancomycin
C. IV fluids
📌 Key point: Severe dehydration requires IV rehydration. Viral gastroenteritis is self-limiting; antibiotics are not needed.
A 28-year-old pregnant woman at 26 weeks presents with watery diarrhea, fever, and vomiting. She denies recent antibiotic use. Stool exam reveals no leukocytes or blood.
Which of the following findings differentiates viral from bacterial diarrhea?
A. Presence of leukocytes in stool
B. Fever >38°C
C. Watery diarrhea
D. Vomiting
A. Presence of leukocytes in stool
📌 Key point: Bacterial diarrhea (e.g., Salmonella, Shigella) has fecal leukocytes. Viral diarrhea (e.g., Rotavirus, Norovirus) is leukocyte-negative.
A 29-year-old pregnant woman at 16 weeks presents with watery diarrhea, vomiting, and mild fever (38°C) for 2 days. She is tolerating oral fluids well.
Which of the following is the most appropriate treatment?
A. Ciprofloxacin
B. Metronidazole
C. Oral rehydration therapy (ORT)
D. IV fluids
C. Oral rehydration therapy (ORT)
📌 Key point: Supportive care and rehydration are the mainstays of treatment for viral gastroenteritis. Antibiotics are not needed.
A 32-year-old pregnant woman at 24 weeks presents with watery diarrhea, abdominal cramps, and fever (38.5°C) for 2 days. She recently ate undercooked chicken. Her stool culture is positive for Salmonella spp. She has no dehydration, and her vital signs are stable.
What is the most appropriate management?
A. Ciprofloxacin
B. Azithromycin
C. Supportive care only
D. IV fluids + Doxycycline
C. Supportive care only
📌 Key point: Non-typhoidal Salmonella (NTS) is usually self-limiting and does not require antibiotics in healthy patients. However, antibiotics (Ciprofloxacin) are used in high-risk patients (e.g., pregnancy, immunocompromised, severe disease).
A 30-year-old pregnant woman at 28 weeks presents with high fever (39.5°C), abdominal pain, and rose-colored spots on her trunk. She recently traveled to a typhoid-endemic area. Blood cultures grow Salmonella Typhi.
What is the first-line treatment?
A. Ciprofloxacin
B. Doxycycline
C. Vancomycin
D. Supportive care only
A. Ciprofloxacin
📌 Key point: Typhoid fever (Salmonella Typhi) presents with high fever, systemic symptoms, and rose spots. Ciprofloxacin is the first-line treatment, but ceftriaxone or azithromycin is preferred in pregnancy.
A 27-year-old pregnant woman at 22 weeks presents with watery diarrhea that became bloody, fever (38.8°C), and abdominal pain. She reports eating undercooked poultry 5 days ago. Stool culture grows Campylobacter jejuni.
What is the most appropriate treatment?
A. Ciprofloxacin
B. Azithromycin
C. Metronidazole
D. Supportive care only
B. Azithromycin
📌 Key point: Campylobacter infection presents with bloody diarrhea, fever, and poultry consumption. Azithromycin is the treatment of choice.
A 35-year-old pregnant woman at 32 weeks presents with profuse, rice-water stools, dehydration, and mild fever (38°C). She recently traveled to an area with poor sanitation and a cholera outbreak.
Which of the following is the best next step in management?
A. Ciprofloxacin
B. Doxycycline
C. IV fluids + Doxycycline
D. Vancomycin
C. IV fluids + Doxycycline
📌 Key point: Vibrio cholerae causes severe watery diarrhea (rice-water stools) and dehydration. IV fluids are the most critical treatment, and Doxycycline is used in outbreaks (Azithromycin for pregnancy).
A 29-year-old pregnant woman at 20 weeks presents with bloody diarrhea, abdominal cramping, and fever (38.7°C). She recently ate undercooked chicken. Stool culture is pending.
Which of the following pathogens is the most likely cause?
A. Campylobacter jejuni
B. Vibrio cholerae
C. Norovirus
D. Enterotoxigenic E. coli (ETEC)
A. Campylobacter jejuni
📌 Key point: Campylobacter is a leading cause of bloody diarrhea linked to poultry consumption. Vibrio (cholera) causes watery diarrhea, not bloody diarrhea.
A 28-year-old pregnant woman at 24 weeks presents with high fever (39.2°C), severe abdominal pain, and bloody diarrhea for the past 2 days. She has no history of travel but mentions that her toddler recently had similar symptoms. Stool microscopy reveals fecal leukocytes and RBCs.
What is the most appropriate treatment?
A. Ciprofloxacin
B. Doxycycline
C. Metronidazole
D. Supportive care only
A. Ciprofloxacin
📌 Key point: Shigella causes severe dysentery with high fever, bloody diarrhea, and person-to-person spread. Ciprofloxacin is the first-line treatment, but Azithromycin is preferred in pregnancy.
A 30-year-old pregnant woman at 28 weeks presents with bloody diarrhea, fever (38.7°C), and severe abdominal cramps. She recently ate a contaminated salad from a local market. Stool culture grows an invasive strain of E. coli.
What is the next best step?
A. Ciprofloxacin
B. Azithromycin
C. Supportive care only
D. Metronidazole
A. Ciprofloxacin
📌 Key point: Invasive E. coli (EIEC) mimics Shigella (bloody diarrhea, fever, abdominal pain) but is treated with antibiotics (Ciprofloxacin or Azithromycin in pregnancy).
A 32-year-old pregnant woman at 30 weeks presents with bloody diarrhea, abdominal pain, and weight loss for the past 10 days. She recently returned from a rural village. Stool microscopy reveals trophozoites with engulfed RBCs.
Which of the following is the most appropriate treatment?
A. Ciprofloxacin
B. Metronidazole
C. Doxycycline
D. Supportive care only
B. Metronidazole
📌 Key point: Entamoeba histolytica causes amebic dysentery with chronic bloody diarrhea and weight loss. Metronidazole is the first-line treatment.
A 35-year-old pregnant woman presents with bloody diarrhea, fever, and cramping. Stool microscopy shows many leukocytes and RBCs, but no parasites.
Which of the following pathogens is most likely responsible?
A. Entamoeba histolytica
B. Shigella spp.
C. Vibrio cholerae
D. Norovirus
B. Shigella spp.
📌 Key point: Shigella is a leading cause of bacterial dysentery with high fever and fecal leukocytes. Entamoeba histolytica has trophozoites with RBCs, not leukocytes.
A 29-year-old pregnant woman at 18 weeks presents with bloody diarrhea, high fever (39.5°C), and hypotension (BP 90/60 mmHg). She is lethargic and has tachycardia.
What is the most appropriate next step?
A. IV fluids + Ciprofloxacin
B. Supportive care only
C. Metronidazole
D. IV Doxycycline
A. IV fluids + Ciprofloxacin
📌 Key point: Shigella can cause severe dehydration and sepsis. IV fluids and Ciprofloxacin (or Azithromycin in pregnancy) are necessary.
A 28-year-old pregnant woman at 8 weeks gestation presents with nausea and occasional vomiting over the past 2 weeks. She is able to tolerate fluids and small meals but has difficulty eating large portions. She denies weight loss or dehydration.
What is the most appropriate first-line treatment?
A. Ondansetron
B. Methylprednisolone
C. Vitamin B₆ (Pyridoxine) + Doxylamine
D. Parenteral nutrition
C. Vitamin B6 (Pyridoxine) + Doxylamine
📌 Key point: First-line management of mild HG includes dietary modifications, Vitamin B6 + Doxylamine, and natural remedies (ginger extract).
A 30-year-old pregnant woman at 10 weeks gestation presents with persistent nausea and vomiting despite taking Vitamin B6 + Doxylamine. She has lost 3 kg (5% of her body weight) but is not dehydrated.
What is the next best step in management?
A. Phenothiazines (Promethazine, Prochlorperazine)
B. Metoclopramide
C. Parenteral Nutrition
D. Glucocorticoids
A. Phenothiazines (Promethazine, Prochlorperazine)
📌 Key point: Phenothiazines are the second-line treatment in moderate HG. Metoclopramide is third-line and is reserved for severe cases or when Phenothiazines fail.
A 27-year-old woman at 12 weeks gestation presents with persistent vomiting, dehydration, and a weight loss of 6% of her pre-pregnancy weight. She has tachycardia (HR 115 bpm), postural hypotension, and dry mucous membranes.
What is the next best step in management?
A. Oral rehydration therapy
B. IV fluids + Thiamine supplementation
C. Phenothiazines
D. Enteral feeding
B. IV fluids + Thiamine supplementation
📌 Key point: Severe HG requires inpatient management with IV fluids and electrolyte replacement. Thiamine must be given before IV dextrose to prevent Wernicke encephalopathy.
A 29-year-old woman at 14 weeks gestation is hospitalized for severe nausea and vomiting despite treatment with IV fluids and Phenothiazines. She continues to lose weight and is unable to tolerate oral intake.
What is the next best step in management?
A. Metoclopramide
B. Methylprednisolone
C. Ciprofloxacin
D. Peripheral Parenteral Nutrition (PPN)
A. Metoclopramide
📌 Key point: Metoclopramide (a dopamine antagonist) is third-line therapy, used when Phenothiazines fail. Steroids (Methylprednisolone) are reserved for intractable cases.
A 32-year-old woman at 15 weeks gestation has severe nausea and vomiting despite Phenothiazines and Metoclopramide. The medical team is considering prescribing Ondansetron.
What is the most important consideration before starting this medication?
A. Ondansetron should be used with caution due to a potential link to birth defects.
B. Ondansetron is contraindicated in pregnancy.
C. Ondansetron is the first-line treatment for HG.
D. Ondansetron should be combined with Ciprofloxacin for best results.
A. Ondansetron should be used with caution due to a potential link to birth defects.
📌 Key point: Ondansetron (Zofran) is effective but controversial due to a potential risk of fetal cardiac and cleft defects. It is used after other antiemetics fail.
A 35-year-old pregnant woman at 18 weeks gestation is admitted for intractable vomiting and confusion. Examination reveals horizontal nystagmus, ataxia, and altered mental status.
What is the most likely diagnosis and appropriate treatment?
A. Hyperemesis gravidarum, treat with Ondansetron
B. Wernicke encephalopathy, treat with IV Thiamine
C. Eclampsia, treat with Magnesium Sulfate
D. Gastroenteritis, treat with Ciprofloxacin
B. Wernicke encephalopathy, treat with IV Thiamine
📌 Key point: Wernicke encephalopathy (confusion, ataxia, nystagmus) is a life-threatening complication of HG due to thiamine deficiency. Always give IV thiamine before dextrose.
A 30-year-old woman at 20 weeks gestation remains unable to tolerate enteral feeding despite IV fluids and multiple antiemetics. She has severe malnutrition and electrolyte imbalances.
What is the next best step?
A. Increase Ondansetron dose
B. Initiate Central Parenteral Nutrition (CPN)
C. Prescribe Ciprofloxacin
D. Discharge home with oral rehydration therapy
B. Initiate Central Parenteral Nutrition (CPN)
📌 Key point: Parenteral nutrition is the last resort for refractory HG when enteral feeding is not possible. It carries risks (sepsis, thrombosis), so it should only be used if absolutely necessary.
Which of the following conditions is NOT an indication for hospitalization in a patient with HG?
A. Persistent vomiting with dehydration
B. Weight loss >5% of pre-pregnancy weight
C. Mild nausea relieved with Vitamin B6
D. Signs of Wernicke encephalopathy (confusion, ataxia, nystagmus)
C. Mild nausea relieved with Vitamin B6
📌 Key point: Mild nausea does not require hospitalization. Severe dehydration, weight loss, or neurological symptoms (Wernicke encephalopathy) are red flags requiring urgent admission.
