DDSEP® 8 Quick Quiz

Correct answer: B. Absence of ganglion cells on rectal biopsy. 
 
Rationale  
Hirschsprung's disease occurs in approximately 1 out of 5,000 live births and is caused by absence of ganglion cells in the myenteric plexus of the intestine. The condition arises from failure of the neural crest cells to fully migrate caudally along the intestine during early gestation, resulting in a distal portion of the intestine being aganglionic. Rectal and distal sigmoid involvement is seen in around 85% of cases, with the other 15 percent involving more proximal intestine. It can rarely involve the entire colon and small intestine. Ganglion cells inhibit local smooth muscles, resulting in the characteristic inability for aganglionic bowel to relax. This lack of inhibition gives rise to the absence of rectoanal inhibitory reflex (RAIRs) during anorectal manometry. The lack of inhibition also produces a transition zone on contrast enema, with the distal aganglionic bowel being narrow and the more proximal bowel containing ganglia being dilated. Lack of meconium passage in the first 48 hours of life raises concern for Hirschsprung's disease. Other causes for possible failure to pass meconium include cystic fibrosis, anorectal malformation, small left colon syndrome, meconium plug syndrome and megacystis-microcolon-intestinal hypoperistalsis syndrome.  
 
References 
Kenny, S et al. Semin Pediatr Surg. 2010 Aug;19(3):194-200. 
Wyllie R et al. Pediatric Gastrointestinal and Liver Disease. 4th edition. Elsevier Saunders, Philadelphia, 2011.

Correct answer: B. Absence of ganglion cells on rectal biopsy. 
 
Rationale  
Hirschsprung's disease occurs in approximately 1 out of 5,000 live births and is caused by absence of ganglion cells in the myenteric plexus of the intestine. The condition arises from failure of the neural crest cells to fully migrate caudally along the intestine during early gestation, resulting in a distal portion of the intestine being aganglionic. Rectal and distal sigmoid involvement is seen in around 85% of cases, with the other 15 percent involving more proximal intestine. It can rarely involve the entire colon and small intestine. Ganglion cells inhibit local smooth muscles, resulting in the characteristic inability for aganglionic bowel to relax. This lack of inhibition gives rise to the absence of rectoanal inhibitory reflex (RAIRs) during anorectal manometry. The lack of inhibition also produces a transition zone on contrast enema, with the distal aganglionic bowel being narrow and the more proximal bowel containing ganglia being dilated. Lack of meconium passage in the first 48 hours of life raises concern for Hirschsprung's disease. Other causes for possible failure to pass meconium include cystic fibrosis, anorectal malformation, small left colon syndrome, meconium plug syndrome and megacystis-microcolon-intestinal hypoperistalsis syndrome.  
 
References 
Kenny, S et al. Semin Pediatr Surg. 2010 Aug;19(3):194-200. 
Wyllie R et al. Pediatric Gastrointestinal and Liver Disease. 4th edition. Elsevier Saunders, Philadelphia, 2011.

Correct answer: B. Absence of ganglion cells on rectal biopsy. 
 
Rationale  
Hirschsprung's disease occurs in approximately 1 out of 5,000 live births and is caused by absence of ganglion cells in the myenteric plexus of the intestine. The condition arises from failure of the neural crest cells to fully migrate caudally along the intestine during early gestation, resulting in a distal portion of the intestine being aganglionic. Rectal and distal sigmoid involvement is seen in around 85% of cases, with the other 15 percent involving more proximal intestine. It can rarely involve the entire colon and small intestine. Ganglion cells inhibit local smooth muscles, resulting in the characteristic inability for aganglionic bowel to relax. This lack of inhibition gives rise to the absence of rectoanal inhibitory reflex (RAIRs) during anorectal manometry. The lack of inhibition also produces a transition zone on contrast enema, with the distal aganglionic bowel being narrow and the more proximal bowel containing ganglia being dilated. Lack of meconium passage in the first 48 hours of life raises concern for Hirschsprung's disease. Other causes for possible failure to pass meconium include cystic fibrosis, anorectal malformation, small left colon syndrome, meconium plug syndrome and megacystis-microcolon-intestinal hypoperistalsis syndrome.  
 
References 
Kenny, S et al. Semin Pediatr Surg. 2010 Aug;19(3):194-200. 
Wyllie R et al. Pediatric Gastrointestinal and Liver Disease. 4th edition. Elsevier Saunders, Philadelphia, 2011.

Correct answer: A. Amyloidosis involving the small intestine 
 
Rationale  
This patient has a protein-losing enteropathy as indicated by his diarrhea, peripheral edema, and positive stool alpha-1 antitrypsin test. Multiple diseases, particularly in their later stages, can be associated with a protein-losing enteropathy including primary intestinal lymphangectasia, Crohn's disease of the small intestine, small intestinal bacterial overgrowth (SIBO), and amyloidosis of the small intestine (A). Celiac disease (B) is not associated with protein-losing enteropathy. While Crohn's disease can be associated with protein-losing enteropathy, ulcerative colitis (C) is not usually associated with it. Small bowel dysmotility (D) does not impact absorption or secretion unless associated with SIBO, making this a wrong answer.

Correct answer: A. Amyloidosis involving the small intestine 
 
Rationale  
This patient has a protein-losing enteropathy as indicated by his diarrhea, peripheral edema, and positive stool alpha-1 antitrypsin test. Multiple diseases, particularly in their later stages, can be associated with a protein-losing enteropathy including primary intestinal lymphangectasia, Crohn's disease of the small intestine, small intestinal bacterial overgrowth (SIBO), and amyloidosis of the small intestine (A). Celiac disease (B) is not associated with protein-losing enteropathy. While Crohn's disease can be associated with protein-losing enteropathy, ulcerative colitis (C) is not usually associated with it. Small bowel dysmotility (D) does not impact absorption or secretion unless associated with SIBO, making this a wrong answer.

Correct answer: A. Amyloidosis involving the small intestine 
 
Rationale  
This patient has a protein-losing enteropathy as indicated by his diarrhea, peripheral edema, and positive stool alpha-1 antitrypsin test. Multiple diseases, particularly in their later stages, can be associated with a protein-losing enteropathy including primary intestinal lymphangectasia, Crohn's disease of the small intestine, small intestinal bacterial overgrowth (SIBO), and amyloidosis of the small intestine (A). Celiac disease (B) is not associated with protein-losing enteropathy. While Crohn's disease can be associated with protein-losing enteropathy, ulcerative colitis (C) is not usually associated with it. Small bowel dysmotility (D) does not impact absorption or secretion unless associated with SIBO, making this a wrong answer.

Q2. Correct answer: B. He should undergo surveillance colonoscopy now and annually thereafter. 
 
Rationale  
PSC diagnosis is the most consistent risk factor for colorectal cancer (CRC) in patients with inflammatory bowel disease. Other identified risk factors include endoscopic extent of the disease (pancolitis), duration of the disease (more than 8 years), age at diagnosis (young), presence of pseudopolyps, and family history of CRC. The current guidelines recommend first surveillance colonoscopy 8-10 years after the diagnosis of ulcerative colitis or Crohn's disease that involves more than one-third of the colon with subsequent surveillance intervals at 1-3 years. However, for patients with a concomitant diagnosis of PSC, the recommendation is to initiate surveillance as soon as the coexisting diagnosis is established, with annual surveillance colonoscopy thereafter.  
High-dose UDCA (more than 28 mg/kg/day) is not recommended in patients with PSC because it was linked to adverse outcomes in this population including decompensated cirrhosis, death, and increased risk of colorectal neoplasia. On the other hand, low-dose UDCA may improve laboratory markers of cholestasis, but with no clear impact on survival or long-term outcomes, its role for chemoprophylaxis in colorectal cancer is still controversial.  
Yearly MRCP is recommended to screen for cholangiocarcinoma.  
 
References  
Lindor KD et al. Am J Gastroenterol. 2015 May;110(5):646-59; quiz 660.  
Lopez A et al. Best Pract Res Clin Gastroenterol. Feb-Apr 2018;32-33:103-109.

Q2. Correct answer: B. He should undergo surveillance colonoscopy now and annually thereafter. 
 
Rationale  
PSC diagnosis is the most consistent risk factor for colorectal cancer (CRC) in patients with inflammatory bowel disease. Other identified risk factors include endoscopic extent of the disease (pancolitis), duration of the disease (more than 8 years), age at diagnosis (young), presence of pseudopolyps, and family history of CRC. The current guidelines recommend first surveillance colonoscopy 8-10 years after the diagnosis of ulcerative colitis or Crohn's disease that involves more than one-third of the colon with subsequent surveillance intervals at 1-3 years. However, for patients with a concomitant diagnosis of PSC, the recommendation is to initiate surveillance as soon as the coexisting diagnosis is established, with annual surveillance colonoscopy thereafter.  
High-dose UDCA (more than 28 mg/kg/day) is not recommended in patients with PSC because it was linked to adverse outcomes in this population including decompensated cirrhosis, death, and increased risk of colorectal neoplasia. On the other hand, low-dose UDCA may improve laboratory markers of cholestasis, but with no clear impact on survival or long-term outcomes, its role for chemoprophylaxis in colorectal cancer is still controversial.  
Yearly MRCP is recommended to screen for cholangiocarcinoma.  
 
References  
Lindor KD et al. Am J Gastroenterol. 2015 May;110(5):646-59; quiz 660.  
Lopez A et al. Best Pract Res Clin Gastroenterol. Feb-Apr 2018;32-33:103-109.

Q2. Correct answer: B. He should undergo surveillance colonoscopy now and annually thereafter. 
 
Rationale  
PSC diagnosis is the most consistent risk factor for colorectal cancer (CRC) in patients with inflammatory bowel disease. Other identified risk factors include endoscopic extent of the disease (pancolitis), duration of the disease (more than 8 years), age at diagnosis (young), presence of pseudopolyps, and family history of CRC. The current guidelines recommend first surveillance colonoscopy 8-10 years after the diagnosis of ulcerative colitis or Crohn's disease that involves more than one-third of the colon with subsequent surveillance intervals at 1-3 years. However, for patients with a concomitant diagnosis of PSC, the recommendation is to initiate surveillance as soon as the coexisting diagnosis is established, with annual surveillance colonoscopy thereafter.  
High-dose UDCA (more than 28 mg/kg/day) is not recommended in patients with PSC because it was linked to adverse outcomes in this population including decompensated cirrhosis, death, and increased risk of colorectal neoplasia. On the other hand, low-dose UDCA may improve laboratory markers of cholestasis, but with no clear impact on survival or long-term outcomes, its role for chemoprophylaxis in colorectal cancer is still controversial.  
Yearly MRCP is recommended to screen for cholangiocarcinoma.  
 
References  
Lindor KD et al. Am J Gastroenterol. 2015 May;110(5):646-59; quiz 660.  
Lopez A et al. Best Pract Res Clin Gastroenterol. Feb-Apr 2018;32-33:103-109.

Q1. Correct answer: E. Emergent angiography 
 
Rationale  
This patient presents with a massive lower GI hemorrhage. After a brisk upper GI bleed was ruled-out with esophagogastroduodenoscopy, the patient continued to hemorrhage and remained hemodynamically unstable. In the setting of a patient with ongoing massive lower GI bleeding who has been ruled out for an upper GI bleed (negative upper endoscopy) and who continues to have hemodynamic instability despite resuscitation, emergent angiography should be pursued in an effort localize and control bleeding.  
Answer A is incorrect because an INR less than 2.5 does not require reversal prior to attempts at hemostasis. Answers B and C are incorrect because, given the patient's altered mental status and hemodynamic changes, she is unlikely to tolerate a bowel preparation and urgent colonoscopy. Also, there is no role for an unprepped colonoscopy in lower GI bleeding due to low yield and poor visualization. Answer D is incorrect because a nuclear-tagged red blood cell scan should be reserved for a patient who is hemodynamically stable.  
 
Reference  
Strate LL, Gralnek IM. Am J Gastroenterol. 2016 Apr;111(4):459-74.

Q1. Correct answer: E. Emergent angiography 
 
Rationale  
This patient presents with a massive lower GI hemorrhage. After a brisk upper GI bleed was ruled-out with esophagogastroduodenoscopy, the patient continued to hemorrhage and remained hemodynamically unstable. In the setting of a patient with ongoing massive lower GI bleeding who has been ruled out for an upper GI bleed (negative upper endoscopy) and who continues to have hemodynamic instability despite resuscitation, emergent angiography should be pursued in an effort localize and control bleeding.  
Answer A is incorrect because an INR less than 2.5 does not require reversal prior to attempts at hemostasis. Answers B and C are incorrect because, given the patient's altered mental status and hemodynamic changes, she is unlikely to tolerate a bowel preparation and urgent colonoscopy. Also, there is no role for an unprepped colonoscopy in lower GI bleeding due to low yield and poor visualization. Answer D is incorrect because a nuclear-tagged red blood cell scan should be reserved for a patient who is hemodynamically stable.  
 
Reference  
Strate LL, Gralnek IM. Am J Gastroenterol. 2016 Apr;111(4):459-74.

Q1. Correct answer: E. Emergent angiography 
 
Rationale  
This patient presents with a massive lower GI hemorrhage. After a brisk upper GI bleed was ruled-out with esophagogastroduodenoscopy, the patient continued to hemorrhage and remained hemodynamically unstable. In the setting of a patient with ongoing massive lower GI bleeding who has been ruled out for an upper GI bleed (negative upper endoscopy) and who continues to have hemodynamic instability despite resuscitation, emergent angiography should be pursued in an effort localize and control bleeding.  
Answer A is incorrect because an INR less than 2.5 does not require reversal prior to attempts at hemostasis. Answers B and C are incorrect because, given the patient's altered mental status and hemodynamic changes, she is unlikely to tolerate a bowel preparation and urgent colonoscopy. Also, there is no role for an unprepped colonoscopy in lower GI bleeding due to low yield and poor visualization. Answer D is incorrect because a nuclear-tagged red blood cell scan should be reserved for a patient who is hemodynamically stable.  
 
Reference  
Strate LL, Gralnek IM. Am J Gastroenterol. 2016 Apr;111(4):459-74.

Correct answer: A. Intravenous proton pump inhibitor drip. 
 
Rationale  
It is important to understand the initial management of patients with bleeding esophageal varices. With voluminous hematemesis, especially from a proximal source like the esophagus, airway protection is crucial so this patient should be intubated. Patients like this are at high risk to develop infected ascites so IV antibiotics should be given. Antibiotics have been shown to decrease mortality in cirrhotic patients admitted with GI bleeding. Somatostatin analogs decrease portal inflow by causing splanchnic vasoconstriction and have been proven to achieve hemostasis and decrease the risk of rebleeding. One has to be cautious with resuscitation efforts, as excessive resuscitation can lead to accelerated bleeding due to increased portal pressures. However, this patient's Hemoglobin concentration is well below the threshold that warrants transfusion, so giving him PRBCs is appropriate. In the acute setting of an upper GI bleed, proton pump inhibitors work to help optimize platelet function by increasing gastric pH. Since the source here is varices in the more pH neutral esophageal environment, intravenous PPI likely has little effect in the acute setting. However after band ligation is performed, it may help decrease the risk of forming post-banding ulcers. Since this patient's banding was performed a month ago, this episode of bleeding is more likely to be from recurrent varices than from a post-banding ulcer.  
 
References  
Garcia-Tsao G et al. Hepatology. 2007 Sep;46(3):922-38.  
Tripathi D et al. Gut. 2015 Nov;64(11):1680-704.

Correct answer: A. Intravenous proton pump inhibitor drip. 
 
Rationale  
It is important to understand the initial management of patients with bleeding esophageal varices. With voluminous hematemesis, especially from a proximal source like the esophagus, airway protection is crucial so this patient should be intubated. Patients like this are at high risk to develop infected ascites so IV antibiotics should be given. Antibiotics have been shown to decrease mortality in cirrhotic patients admitted with GI bleeding. Somatostatin analogs decrease portal inflow by causing splanchnic vasoconstriction and have been proven to achieve hemostasis and decrease the risk of rebleeding. One has to be cautious with resuscitation efforts, as excessive resuscitation can lead to accelerated bleeding due to increased portal pressures. However, this patient's Hemoglobin concentration is well below the threshold that warrants transfusion, so giving him PRBCs is appropriate. In the acute setting of an upper GI bleed, proton pump inhibitors work to help optimize platelet function by increasing gastric pH. Since the source here is varices in the more pH neutral esophageal environment, intravenous PPI likely has little effect in the acute setting. However after band ligation is performed, it may help decrease the risk of forming post-banding ulcers. Since this patient's banding was performed a month ago, this episode of bleeding is more likely to be from recurrent varices than from a post-banding ulcer.  
 
References  
Garcia-Tsao G et al. Hepatology. 2007 Sep;46(3):922-38.  
Tripathi D et al. Gut. 2015 Nov;64(11):1680-704.

Correct answer: A. Intravenous proton pump inhibitor drip. 
 
Rationale  
It is important to understand the initial management of patients with bleeding esophageal varices. With voluminous hematemesis, especially from a proximal source like the esophagus, airway protection is crucial so this patient should be intubated. Patients like this are at high risk to develop infected ascites so IV antibiotics should be given. Antibiotics have been shown to decrease mortality in cirrhotic patients admitted with GI bleeding. Somatostatin analogs decrease portal inflow by causing splanchnic vasoconstriction and have been proven to achieve hemostasis and decrease the risk of rebleeding. One has to be cautious with resuscitation efforts, as excessive resuscitation can lead to accelerated bleeding due to increased portal pressures. However, this patient's Hemoglobin concentration is well below the threshold that warrants transfusion, so giving him PRBCs is appropriate. In the acute setting of an upper GI bleed, proton pump inhibitors work to help optimize platelet function by increasing gastric pH. Since the source here is varices in the more pH neutral esophageal environment, intravenous PPI likely has little effect in the acute setting. However after band ligation is performed, it may help decrease the risk of forming post-banding ulcers. Since this patient's banding was performed a month ago, this episode of bleeding is more likely to be from recurrent varices than from a post-banding ulcer.  
 
References  
Garcia-Tsao G et al. Hepatology. 2007 Sep;46(3):922-38.  
Tripathi D et al. Gut. 2015 Nov;64(11):1680-704.

Correct answer: A. Diphyllobothrium latum. 
 
Rationale  
This is likely a tapeworm infection with Diphyllobothrium latum. D. latum infection can be acquired from ingesting certain forms of freshwater fish, and those who consume raw fish, including sushi, are at increased risk. The classical manifestation of infection with D. latum is megaloblastic anemia due to vitamin B12 deficiency. D. latum has a unique affinity for vitamin B12 and therefore competes with the host for absorption. Humans become infected with Taenia by ingesting raw or undercooked infected meat containing cysticerci. Infection with Hymenolepis is common in children secondary to breaches in fecal-oral hygiene. Most infections are asymptomatic.  
 
Reference  
Webb C, Cabada MM. Curr Opin Infect Dis. 2017 Oct;30(5):504-10. 

Correct answer: A. Diphyllobothrium latum. 
 
Rationale  
This is likely a tapeworm infection with Diphyllobothrium latum. D. latum infection can be acquired from ingesting certain forms of freshwater fish, and those who consume raw fish, including sushi, are at increased risk. The classical manifestation of infection with D. latum is megaloblastic anemia due to vitamin B12 deficiency. D. latum has a unique affinity for vitamin B12 and therefore competes with the host for absorption. Humans become infected with Taenia by ingesting raw or undercooked infected meat containing cysticerci. Infection with Hymenolepis is common in children secondary to breaches in fecal-oral hygiene. Most infections are asymptomatic.  
 
Reference  
Webb C, Cabada MM. Curr Opin Infect Dis. 2017 Oct;30(5):504-10. 

Correct answer: A. Diphyllobothrium latum. 
 
Rationale  
This is likely a tapeworm infection with Diphyllobothrium latum. D. latum infection can be acquired from ingesting certain forms of freshwater fish, and those who consume raw fish, including sushi, are at increased risk. The classical manifestation of infection with D. latum is megaloblastic anemia due to vitamin B12 deficiency. D. latum has a unique affinity for vitamin B12 and therefore competes with the host for absorption. Humans become infected with Taenia by ingesting raw or undercooked infected meat containing cysticerci. Infection with Hymenolepis is common in children secondary to breaches in fecal-oral hygiene. Most infections are asymptomatic.  
 
Reference  
Webb C, Cabada MM. Curr Opin Infect Dis. 2017 Oct;30(5):504-10. 

Q2. Correct answer: A.  
 
Rationale  
Tropical sprue occurs in patients from or travelers to endemic areas near the equator, such as Puerto Rico, Haiti, Cuba, Southeast Asia, and India for at least 2 weeks to a month and has a likely infectious etiology, but the exact organism(s) has not been identified. Patients may present with malabsorption, steatorrhea, weight loss, and fatigue. Laboratory testing shows anemia, B12 and folate deficiency, and increased fecal fat. Biopsies of the small bowel during upper endoscopy show villous blunting with negative celiac serologies. Treatment is a 3- to 6-month course of tetracycline 250 mg orally four times daily with folate 5 mg orally daily. The macrocytic anemia, normal iron studies, and low vitamin B12 and folate levels argue against celiac disease, so this patient is unlikely to respond to a gluten-free diet.  
 
References  
Ghoshal UC et. al. Curr Gastroenterol Rep. 2014;16(6):391.  
Batheja MJ et. al. Case Rep Gastroenterol. 2010 May 19;4(2):168-172.  
Jansson-Knodell CL et al. Mayo Clin Proc. 2018 Apr;93(4):509-517.

Q2. Correct answer: A.  
 
Rationale  
Tropical sprue occurs in patients from or travelers to endemic areas near the equator, such as Puerto Rico, Haiti, Cuba, Southeast Asia, and India for at least 2 weeks to a month and has a likely infectious etiology, but the exact organism(s) has not been identified. Patients may present with malabsorption, steatorrhea, weight loss, and fatigue. Laboratory testing shows anemia, B12 and folate deficiency, and increased fecal fat. Biopsies of the small bowel during upper endoscopy show villous blunting with negative celiac serologies. Treatment is a 3- to 6-month course of tetracycline 250 mg orally four times daily with folate 5 mg orally daily. The macrocytic anemia, normal iron studies, and low vitamin B12 and folate levels argue against celiac disease, so this patient is unlikely to respond to a gluten-free diet.  
 
References  
Ghoshal UC et. al. Curr Gastroenterol Rep. 2014;16(6):391.  
Batheja MJ et. al. Case Rep Gastroenterol. 2010 May 19;4(2):168-172.  
Jansson-Knodell CL et al. Mayo Clin Proc. 2018 Apr;93(4):509-517.

Q2. Correct answer: A.  
 
Rationale  
Tropical sprue occurs in patients from or travelers to endemic areas near the equator, such as Puerto Rico, Haiti, Cuba, Southeast Asia, and India for at least 2 weeks to a month and has a likely infectious etiology, but the exact organism(s) has not been identified. Patients may present with malabsorption, steatorrhea, weight loss, and fatigue. Laboratory testing shows anemia, B12 and folate deficiency, and increased fecal fat. Biopsies of the small bowel during upper endoscopy show villous blunting with negative celiac serologies. Treatment is a 3- to 6-month course of tetracycline 250 mg orally four times daily with folate 5 mg orally daily. The macrocytic anemia, normal iron studies, and low vitamin B12 and folate levels argue against celiac disease, so this patient is unlikely to respond to a gluten-free diet.  
 
References  
Ghoshal UC et. al. Curr Gastroenterol Rep. 2014;16(6):391.  
Batheja MJ et. al. Case Rep Gastroenterol. 2010 May 19;4(2):168-172.  
Jansson-Knodell CL et al. Mayo Clin Proc. 2018 Apr;93(4):509-517.

Correct answer: A. 
 
Rationale  
This patient has scromboid poisoning, which occurs when histidine is converted to histamine by bacterial enzymes in improperly refrigerated fish. Most cases in the United States are reported in Hawaii, Florida, and California and involve consumption of affected tuna, mackerel, mahi-mahi, sardines, herring, and other fish. Onset of symptoms occurs about 1 hour after eating the suspect fish; the patient may experience hot flashes, facial flushing, hives, upper body rash, perioral paresthesias or edema, palpitations, lightheadedness, nausea, vomiting, and abdominal pain. Symptoms typically resolve within 1 day, though some patients may experience a longer course. Supportive care and either oral or intravenous administration of antihistamines may be used to improve symptoms. Evaluation of airway patency is also important. Scromboid poisoning may be prevented by immediate refrigeration of fresh fish to below 40°C.  
Although ACE inhibitor induced angioedema may cause facial swelling, the time course of the disease and associated risk factors favor scromboid poisoning. Ingestion of Bacillus cereus or Staphylococcus aureus would not be expected to cause flushing, tachycardia, and upper body rash. Ciguatera poisoning has a less immediate onset of symptoms, is associated with neurologic symptoms, and has a more protracted course. This patient is not likely to have an allergy to seafood.  
 
Reference  
Hungerford JM. Toxicon. 2010 Aug 15;56(2):231-43.

Correct answer: A. 
 
Rationale  
This patient has scromboid poisoning, which occurs when histidine is converted to histamine by bacterial enzymes in improperly refrigerated fish. Most cases in the United States are reported in Hawaii, Florida, and California and involve consumption of affected tuna, mackerel, mahi-mahi, sardines, herring, and other fish. Onset of symptoms occurs about 1 hour after eating the suspect fish; the patient may experience hot flashes, facial flushing, hives, upper body rash, perioral paresthesias or edema, palpitations, lightheadedness, nausea, vomiting, and abdominal pain. Symptoms typically resolve within 1 day, though some patients may experience a longer course. Supportive care and either oral or intravenous administration of antihistamines may be used to improve symptoms. Evaluation of airway patency is also important. Scromboid poisoning may be prevented by immediate refrigeration of fresh fish to below 40°C.  
Although ACE inhibitor induced angioedema may cause facial swelling, the time course of the disease and associated risk factors favor scromboid poisoning. Ingestion of Bacillus cereus or Staphylococcus aureus would not be expected to cause flushing, tachycardia, and upper body rash. Ciguatera poisoning has a less immediate onset of symptoms, is associated with neurologic symptoms, and has a more protracted course. This patient is not likely to have an allergy to seafood.  
 
Reference  
Hungerford JM. Toxicon. 2010 Aug 15;56(2):231-43.

Correct answer: A. 
 
Rationale  
This patient has scromboid poisoning, which occurs when histidine is converted to histamine by bacterial enzymes in improperly refrigerated fish. Most cases in the United States are reported in Hawaii, Florida, and California and involve consumption of affected tuna, mackerel, mahi-mahi, sardines, herring, and other fish. Onset of symptoms occurs about 1 hour after eating the suspect fish; the patient may experience hot flashes, facial flushing, hives, upper body rash, perioral paresthesias or edema, palpitations, lightheadedness, nausea, vomiting, and abdominal pain. Symptoms typically resolve within 1 day, though some patients may experience a longer course. Supportive care and either oral or intravenous administration of antihistamines may be used to improve symptoms. Evaluation of airway patency is also important. Scromboid poisoning may be prevented by immediate refrigeration of fresh fish to below 40°C.  
Although ACE inhibitor induced angioedema may cause facial swelling, the time course of the disease and associated risk factors favor scromboid poisoning. Ingestion of Bacillus cereus or Staphylococcus aureus would not be expected to cause flushing, tachycardia, and upper body rash. Ciguatera poisoning has a less immediate onset of symptoms, is associated with neurologic symptoms, and has a more protracted course. This patient is not likely to have an allergy to seafood.  
 
Reference  
Hungerford JM. Toxicon. 2010 Aug 15;56(2):231-43.

Q2. Correct answer: A. CT scan. 
 
Rationale  
Given the change in bowel habits, colonoscopy in indicated to evaluate for inflammation. Anorectal manometry is helpful in evaluating sphincter function. Endoanal ultrasound can identify anal sphincter defects in the internal or external anal sphincter. Digital rectal exam is important in evaluating the anal area for skin tags, fissures, or scar. Digital exam can evaluate for resting anal sphincter tone and squeeze, pelvic floor descent and strength of the pelvic floor muscles. CT is unlikely to contribute to the evaluation of a functional disorder.  
 
Reference  
Bharucha AE et al. Gastroenterology. 2006 Apr;130(5):1510-8.

Q2. Correct answer: A. CT scan. 
 
Rationale  
Given the change in bowel habits, colonoscopy in indicated to evaluate for inflammation. Anorectal manometry is helpful in evaluating sphincter function. Endoanal ultrasound can identify anal sphincter defects in the internal or external anal sphincter. Digital rectal exam is important in evaluating the anal area for skin tags, fissures, or scar. Digital exam can evaluate for resting anal sphincter tone and squeeze, pelvic floor descent and strength of the pelvic floor muscles. CT is unlikely to contribute to the evaluation of a functional disorder.  
 
Reference  
Bharucha AE et al. Gastroenterology. 2006 Apr;130(5):1510-8.

Q2. Correct answer: A. CT scan. 
 
Rationale  
Given the change in bowel habits, colonoscopy in indicated to evaluate for inflammation. Anorectal manometry is helpful in evaluating sphincter function. Endoanal ultrasound can identify anal sphincter defects in the internal or external anal sphincter. Digital rectal exam is important in evaluating the anal area for skin tags, fissures, or scar. Digital exam can evaluate for resting anal sphincter tone and squeeze, pelvic floor descent and strength of the pelvic floor muscles. CT is unlikely to contribute to the evaluation of a functional disorder.  
 
Reference  
Bharucha AE et al. Gastroenterology. 2006 Apr;130(5):1510-8.

Q1. Correct answer: C. Esophagogastric junction outflow obstruction.  
 
Rationale  
Recent studies recognized the role of medications in inducing esophageal motor disorders. Opiates have been shown to be associated with esophagogastric junction outflow obstruction, achalasia (not type 1), and other hypercontractile esophageal abnormalities.  
 
Reference  
Camilleri M et al. Clin Gastroenterol Hepatol. 2017 Sep;15(9):1338-49.

Q1. Correct answer: C. Esophagogastric junction outflow obstruction.  
 
Rationale  
Recent studies recognized the role of medications in inducing esophageal motor disorders. Opiates have been shown to be associated with esophagogastric junction outflow obstruction, achalasia (not type 1), and other hypercontractile esophageal abnormalities.  
 
Reference  
Camilleri M et al. Clin Gastroenterol Hepatol. 2017 Sep;15(9):1338-49.

Q1. Correct answer: C. Esophagogastric junction outflow obstruction.  
 
Rationale  
Recent studies recognized the role of medications in inducing esophageal motor disorders. Opiates have been shown to be associated with esophagogastric junction outflow obstruction, achalasia (not type 1), and other hypercontractile esophageal abnormalities.  
 
Reference  
Camilleri M et al. Clin Gastroenterol Hepatol. 2017 Sep;15(9):1338-49.