Gastro USMLE**

Question 1

72 yo male in ED with sudden onset of very severe mid abdominal pain. He has a histroy of aortic stenosis, CAD, and afib. He has been losing weight. His abdo exam is relatively benign compared to his severe pain. His stool is heme positive. What is the most likely dx? what is the most accurate test? what is the most effective therapy?

Answer 1

Most likely dx; mesenteric ischemia (presents with severe abdo pain that is far more intense than the benign exam. occurs in association with CAD, valvular heart disease and a fib) Mesenteric ischemia is often from an acute embolic event to the mesenteric artery. Most accurate test? Mesenteric arteriography. Most effective therapy? Exploratory laporotomy for possibel resection of teh affected segment of bowel.

Question 2

Man in ED with multiple episodes of vomiting blood. He also has diarrhea and black stool. What is the most likely dx when bleeding preceded by severe and violent retching?

Answer 2

Mallory-weiss tears are non transmural tears in the esophageal mucosa. This is preceded by repeated episodes of wretching or vomiting for any reason. Any form of upper GIB can result in melena if more than 100 - 200ml of blood is lost

Question 3

Man in ED with multiple episodes of vomiting blood. He also has diarrhea and black stool. What is the most likely dx when mid epigastric pain that was relieved by food?

Answer 3

Duodenal Ulcer is the most common cause of upper GIB. Duodenal ulcers present with epigastric pain. The pain can be relieved by food. Endoscopy is necessary for a specific diagnosis.

Question 4

Man in ED with multiple episodes of vomiting blood. He also has diarrhea and black stool. What is the most likely dx when he is al alcoholic with low platelets and spider angiomata. THe volume of hematemesis is enormous.

Answer 4

Esophageal varices lead to the highest mortality of any form of GIB. The case will describe liver disease. Severe cirrhosis is often associated with splenomegaly with splenic sequestration of platelets.

Question 5

A man is brough to the ED with multiple episodes of red blood in stool. WHat is the most likely dx? What is the most accurate diagnostic test?

Answer 5

Most accurate dx is lower GIB (most commonly caused by diverticulosis and angiodysplasia. Other causes are polyps, colon ca and ischemic colitis.
Colonoscopy is the most accurate diagnostic test of LGIB. There is no definitive ay to determine the precise etiology of colonic bleeding without endoscopy. Barium studies, angiography and CT scanning cannot lead to a specific diagnosis.
Hemorrhoids may also lead to red blood in stools. Often the hisotry will mention that the patient notes hematochezia and/or red blood when wiping.

Question 6

A 32 yo male comes into office with one day of diarrhea. What is the most likely diagnosis when there is vomiting. He recently ate chinese food?

Answer 6

Bacillus Cereus. (associated with refried chinese rice. As with staph aureus, there is no blood in the stool beacuase it is a preformed toxin. Both organisms often present with vomiting)

Question 7

A 32 yo male comes into office with one day of diarrhea. What is the most likely diagnosis when He has recently been on a camping trip. He has bloating and flatulence.

Answer 7

Giardiasis. (associated with unfiltered water, such as found on camping trips. Bloating and flatus are common. Giardiasis can mimic fat malabsorption.

Question 8

A 32 yo male comes into office with one day of diarrhea. What is the most likely diagnosis when he is HIV + with <50 CD4 cells

Answer 8

Cryptosporidiosis is an organism that is common in those with AIDs and profound immunosuppression. The diarrhea is often chronic and responds to treatment of the underlying HIV disease.

Question 9

A 32 yo male comes into office with one day of diarrhea. What is the most likely diagnosis when there is flushing and wheezing. He ate fresh fish on the same day.

Answer 9

Scombroid is a histamine fish poisoning. Bacteria that produce histamine infect tuna, mackerel, or mahi mahi, resulting in the rapid onset of diarrhea, vomiting, flushing and wheezing.

Question 10

A 35 yo woman comes with several months of crampy lower abdo pain. She has diarrhea, but there is never blood in the stool. There is no wt loss. What is the most likely dx whenthe diarrhea alternates with constipation. THe pain is relieved with a BM. All sx are less at night.

Answer 10

Irritable Bowel Syndrome ( a pain syndrome that often has diarrhea alternaitng with constipation. All symptoms are less at night and the pain can be relieved by a BM. the key feature to teh diagnosis of IBS is abdo pain with completely normal tests).

Question 11

A 35 yo woman comes with several months of crampy lower abdo pain. She has diarrhea, but there is never blood in the stool. There is no wt loss. What is the most likely dx when she has episodes of flushing and hypotension.

Answer 11

Carcinoid Syndrome (episodes of diarrhea, flsuhing, and hypotension. Urinary 5-HIAA confirms diagnosis)

Question 12

A 35 yo woman comes with several months of crampy lower abdo pain. She has diarrhea, but there is never blood in the stool. There is no wt loss. What is the most likely dx when a dietary change relives all symptoms in 24h.

Answer 12

Lactose intolerance (presents with diarrhea in the absence of weight loss. removal of milk products and cheese relieves symptoms. Celiac disease would lead to weight loss and would need severeal weeks for symptoms to resolve. Celiac disease would also be related to gluten containing products).

Question 13

Healthy 40yo male in ED with several days of bloody diarrhea which occurred four times today. He has a temp of 102F, P 105, BP 112/78. What is the most likely diagnosis when he has been eating raw oysters and clams.

Answer 13

Vibrio parahemolyticus is stransmitted by shellfish such as oysters and clams. Shellfish are filter feeders that concentrate organisms as they feed themselves.

Question 14

Healthy 40yo male in ED with several days of bloody diarrhea which occurred four times today. He has a temp of 102F, P 105, BP 112/78. What is the most likely diagnosis when he has had mussels. He has a history of liver disease. Physical shows bullous skin lesions.

Answer 14

Vibrio vulnificus is associated with diarrhea in pateitns with liver disease who consume contaminated shellfish. There is also an increased incidence of developing bullous skin lesions.

Question 15

Healthy 40yo male in ED with several days of bloody diarrhea which occurred four times today. He has a temp of 102F, P 105, BP 112/78. What is the most likely diagnosis when anemia, thrombocytopenia, and an elevated creatinine are present. The retic count, bilirubin and LDH are elevated, haptoglobin is low.

Answer 15

E coli 0157:H7 is associated with the development of HUS

Question 16

A patient comes in with epigastric discomfort that radiates up into the chest and is substernal in location. He has a cough, hoarseness, and a bad taste in his mouth, like he is sucking on pennies. What is the most likely dx? What is the most accurate test? What would you do first in the management of this patient?

Answer 16

GERD leads to epigastric pain that radiates up under the sternum. In addition, the acid hits the back of the tongue, leading to a bitter taste in the mouth. When acid hits the vocal cords there is hoarseness and sometimes coughin and wheezing. The most accurate test of GERD is the 24h pH monitor. The first thing to do for GERD is to start therapy with a PPI. This is both diagnostic and therapeutic.

Question 17

A man is evaluated in the office for several weeks of epigastric discomfort and pain. What is the most likely diagnosis when he is an alcoholic and there is epigastric tenderness?

Answer 17

Pancreatitis is the only form of acute epigastric pain that is reliably associated with tenderness. Gastritis and ulcer disease are rarely associated with epigastric tenderness unless a perforation has occurred.

Question 18

A man is evaluated in the office for several weeks of epigastric discomfort and pain. What is the most likely diagnosis when he has no other symptoms and all the labs are normal?

Answer 18

Non Ulcer Dyspepsia is the most common cause of epigastric discomfort. There is epigastric pain with an entirely normal exam, including a normal endoscopy. The etiology is unknown.

Question 19

A man is evaluated in the office for several weeks of epigastric discomfort and pain. What is the most likely diagnosis when he has had two episodes of black stool and the pain is better with food?

Answer 19

Ulcer disease is the most common cause of upperGIB. Ulcers are not as common as non ulcer dyspepsia as a cause of epigastric pain. Duodenal ulcers are more often improved with eating. Gastric ulcers are worsened with eating. An upper endoscopy can be diagnostic.

Question 20

22 yo female comes to the office with recurrent episodes of diarrhea, fatigue, and abdominal pain. There is occasional blood. In addition, she has joint pain, erythema nodosum, and uveitis. The hematocrit is 32, MCV is 90, and the ESR is elevated. Alk phos is elevated but the bili is normal. Stool culture and ova/parasite exam show nothing. What is the most likely diagnosis when rectal bleeding is common. ANCA are present and ASCA (anti saccharomyces cerevisiae antibodies) are negative.

Answer 20

UC presents with recurrent episodes of blood diarrhea and pus from the rectum. The extra intestinal manifestations of both forms of IBD are identical. Both give joint, skin, and ocular symptoms. Both can give sclerosing cholangitis. UC give positive ANCA and negative ASCA

Question 21

22 yo female comes to the office with recurrent episodes of diarrhea, fatigue, and abdominal pain. There is occasional blood. In addition, she has joint pain, erythema nodosum, and uveitis. The hematocrit is 32, MCV is 90, and the ESR is elevated. Alk phos is elevated but the bili is normal. Stool culture and ova/parasite exam show nothing. What is the most likely diagnosis when perianal and small bowel disease is present. A fistula was present in the past. Granulomas are present on biopsy. ANCA is negative and ASCA is positive. A mass is palpable in the abdomen.

Answer 21

Chrons Disease gives small bowel disease, fistulae and perianal disease in addition to skip lesions. Granulomas are characteristic of CD. CD gives negative ANCA and positive ASCA. Anemia, low albumin levels, and a high ESR can be found in both diseases. Chrons is transmural inflammation whereas UC is mucosal only.

Question 22

A woman is evaluated in the office for moderate hepatomegaly and elevation of AST, ALT and bilirubin. A few spider nevi are present on the skin what is the most likely diagnosis whenteh ANA and anti smooth muscle antibody are positive. Gammaglobulins are also elevated and there is a brisk response to prednisone.

Answer 22

Autoimmune hepatitis presents with hepatomegaly and the stigmata of chronic liver disease. The ANA is often positive and gammaglobulin levels are elevated. Less reliable findings are the presence of anti smooth muscle antibodies and the liver-kidney microsomal antibody. Autoimmune hepatitis responds briskly to prednisone use.

Question 23

A woman is evaluated in the office for moderate hepatomegaly and elevation of AST, ALT and bilirubin. A few spider nevi are present on the skin what is the most likely diagnosis when hepatomegaly is the main finding in a woman with diabetes, obesity, and hyper triglyceridemia. The ALT is slightly higher than the AST. Fatty liver is seen on imaging. She does not drink alcohol.

Answer 23

Non-alcoholic steatohepatitis (NASH) is associated with obesity, diabetes and hyperlipidemia. The liver biopsy shows the fatty infiltation you would see in a patient with alcoholic liver disease but there is no history of significant alcohol use. NASH is associated with an ALT slightly greater than AST. This is the opposite in a person with alcoholic liver disease. There is no definitive treatment for NASH besides losing weight and controlling the diabetes and hyperlipidemia.

Question 24

A 38yo male with wt loss, flatulence, diarrhea, malodourous stool and weakness. He bruises easily and his calcium levels are low. Hematocrit is 29. Sudan black stain is postivie. What is the most likely diagnosis if chronic alcoholic with epigastric pain and normal folate and iron levels. Calcification of the pancreas on CT. Lipase and amylase are normal.

Answer 24

Chronic pancreatitis is most often from etoh. The iron and folate levels are normal. Lipase and amylase levels are normal in most patients with far advanced chronic pancreatitis. Calcifications are present on CT scan of the pancreas in only 70 - 80% of patients. The most accurate diagnostic test is a secretin stimulation test. Secretin should provoke the release of bicarb rich pancreatic enzymes in the normal patient.

Question 25

A 38yo male with wt loss, flatulence, diarrhea, malodourous stool and weakness. He bruises easily and his calcium levels are low. Hematocrit is 29. Sudan black stain is postivie. What is the most likely diagnosis if iron deficiency is present. Folate is low. He has a skin rash with vesicles. Anti-gliadin and tissue transglutaminase antibodies are positive.

Answer 25

Celiac disase and chronic pancreatitis both present with steatorrhea and weight loss. Both disease lead to malabsorption of fat which is associated with the loss of calcium and vitamin K, easy bruising, and malabsorption of vitamin B12. Only celiac disease leads to malabsorption of iron and folate. Iron and folate need an intact bowel wall to be absorbed but do not need pancreatic enzymes. to be absorbed. The most accurate diagnostic test for celiac disease is a small bowel biopsy.

Question 26

A man comes in with dysphagia and weight loss what is the most likely diagnosis when its a younger pt (<50yo) with dysphagia for both solids and liquids.

Answer 26

Achalasia. is associated with dysphagia for both solids and liquids at the same time. It is not progressive. THere is no association with smoking or drinking.

Question 27

A man comes in with dysphagia and weight loss what is the most likely diagnosis when a 65 yo man with long history of alcohol and tobacco use. Dysphagia begins with solid food and progresses to difficulty with liquids.

Answer 27

Esophageal Cancer. gives dysphagia first for solid food, then for liquids. Cancer is progressively worse. Achalasia is not.

Question 28

A man comes in with dysphagia and weight loss what is the most likely diagnosis when foul breath and regurgitation food on the pillow in the morning.

Answer 28

Zenkers Diverticulum is associated with foul smelling breath. Do not use NG or endoscope because of risk of perforation.

Question 29

A man comes in with dysphagia and weight loss what is the most likely diagnosis when history of scleroderma and reflux symtpoms.

Answer 29

Scleroderma esophagitis leads to reflux disease beacuse the esophagus is not capable of contracting. Scleroderma + reflux = scleroderma esophagitis. GIve PPI. Look for sx of CREST sydndrom

Question 30

A man comes in with dysphagia and weight loss what is the most likely diagnosis when chest pain that comes and goes is VERY severe and not associated with eating.

Answer 30

Spastic disorders of the esophagus present with pain not related to eating and exertion. To answer this question, it must include a negative EKG and stress test so you do not answer “angina”. Esophageal manometry can be diagnostic.

Question 31

A man comes in for evaluation of weight loss, diarrhea that is foul - smelling and easy bruising. The calcium level is low and the sudan black stain is positive. What is the most likely diagnosis when he has arthralgia, fever, and cognitive defects. There are ocular abnormalities such as nystagmus. Adenopathy is present. Biopsy of the duodenum shows PAS - positive organisms.

Answer 31

Whipples disease is a cause of malabsorption in association with arthralgia, fever, and CNS abnormalities. The key to answering the most likely diagnosis question is the presence of PAS positive organisms. The best initial therapy is a year of septra.

Question 32

A man comes in for evaluation of weight loss, diarrhea that is foul - smelling and easy bruising. The calcium level is low and the sudan black stain is positive. What is the most likely diagnosis when a patient from the Carribean has severe folate and vitamin B12 deficiency. Biopsy shows abnormal villi with lymphocytic infiltration. Antigliadin and anti-endomysial antibodies are negative.

Answer 32

Tropical Sprue. Is the answer when malabsorption is present in a patient with fat malabsorption in association with severe folate and B12 malabsorption. The question must give the history of a person from the carribean or India. On biopsy, the villi are abnormal with inflammatory cells but they are not as flat as those seen in celiac disease. Treatment is with tetracycline and folate.

Question 33

An alcoholic man is admitted with severe epigastric abdominal pain, nausea, and vomiting. He is restless with a mild fever. What is the most likely diagnosis when the patient has an elevation of his amylase and lipase levels as well as the urinary trypsinogen activation peptide. Ct scan shows inflammation.

Answer 33

Acute pancreatitis. (Occurs in alcoholics and those with gallstone obstructing the ducts. Epigastric pain, nausea, and vomiting are present. The key to diagnosis is epigastric tenderness in an alcoholic. Trypsinogen-activating peptide is elevated. Treatment is pain control, IVF, and NPO until pain is reolves

Question 34

An alcoholic man is admitted with severe epigastric abdominal pain, nausea, and vomiting. He is restless with a mild fever. What is the most likely diagnosis when the CT scan shows necrosis of >30%

Answer 34

Necrotizing Pancreatitis on a CT scan of the abdo is much more important as a prognostic factor than Ransons criteria. Patients with severe necrosis should undergo a biopsy to see if an infection is present. Necrotizing pancreatitis may benefit form antibiotics such an imipenem to prevent infectino.

Question 35

An alcoholic man is admitted with severe epigastric abdominal pain, nausea, and vomiting. He is restless with a mild fever. What is the most likely diagnosis when CT scan shows necrosis and biopsy shows gram negative organisms.

Answer 35

Infected necrotizing pancreatitis. can be diagnosed only by biopsy or surgery. These patients have nearly a 10% mortality without surgical debridement.

Question 36

A woman comes in with severe itching, hepatomegaly, and elevation of alkaline phosphatases and GGTP. What is the most likely diagnosis when she has a history of IBD. Over time the bilirubin level begins to elevate.

Answer 36

Primary sclerosing cholangitis occurs in those with IBD. The alk phosphatase is elevated and the bilirubin only elevates much later in the disease. Definitive diagnosis is by ERCP. Treatment is with ursodeoxycholic acid, but this is of limited effect.

Question 37

A woman comes in with severe itching, hepatomegaly, and elevation of alkaline phosphatases and GGTP. What is the most likely diagnosis when middle aged woman with xanthomas, fat soluble vitamin malabsorption, hyperlipidemia, and skin hyperpigmentation.

Answer 37

Primary biliary cirrhosis occurs in middle aged women who present with itching and an elevated alk phosphatase. THe most accurate test is the anti mitochondrial antibody. Treatment is with ursodeoxycholic acid, which has a limited benefit.

Question 38

A young man is referred to you by psychiatry for evaluation of a tremor and choreiform movement disorder. He was admitted for paranoia and psychosis but was found to have an elevation of his transaminases and a coombs-negative hemolytic anemia. What is the most likely diagnosis, what is the most accurate diagnostic test, what is the therapy?

Answer 38

Wilsons disease (from teh deposition of copper in the brain, liver and kidneys, in addition there is coombs negative hemolytic anemia. look for liver disease with a movement disorder and psychosis). Wilsons disease is diagnosed by finding kayser fleischer rings on slit lamp examination as well as a low level of ceruloplasmin, which is the copper carrying protein in the body. There is increased urinary copper excretion, although the single most accurate test is an increased copper level on biopsy. Penicilamine is the treatment that removes copper from the body.

Question 39

A middle aged man comes in for evaluation of the joint pains and fatigue. He has hepatomegaly on examination, and skin hyperpigmentation. Diabetes has developed over the past few months. He has lost libido adn has developed ED. Liver function testing is elevated. Echo shows restrictive cardiomyopathy. what is the most likely dx, what is the most accurate diagnostic test, what is the therapy.

Answer 39

Hemochromatosis. Iron deposition in multiple organs in the body, especially the liver. Cirrhosis will develop if untreated in 60% of the patients, and HCC in 15 - 20%. Another 15% will die of cardiac involvement. Iron deposition leads to diabetes, pseudogout, skin hyperpigmentation and erectile dysfuntion. The latter is from iron deposition in the pituitary and loss of gonadoptropins. The best initial test is iron studies with an elevated iron and ferritin level and low iron binding capcity. This is a high iron saturation. This prompts the most accurate tests, which are the HFE gene mutation. Liver biopsy with increased iron is the single most accurate test. Phlebotomy is the most effective way to remove iron from the body.

Question 40

A man comes to the ED with abdominal pain, tenderness and fever. What is the most likely diagnosis when there is a hsitory of alcoholic cirrhosis and ascites. Blood pressure and pulse are normal

Answer 40

Spontaneous bacterial peritonitis occurs with ascites. The diagnosis is based on asitic fluid cell count of >250 neutrophils. Culture of the fluid should be injected into blood culture bottles. Most commonly, SBP is from a single organism, such as E.Coli. THe ascitic fluid protein level is low. Treatment is with cefotaxime. Ascitic fluid should be sent for gram stain, culture, protein, albumin, CDH, amylase and cell count.

Question 41

A man comes to the ED with abdominal pain, tenderness and fever. What is the most likely diagnosis when history of peptic ulcer disease. He has a BP of 86/60 and pulse of 120, and there is rebound tenderness on examination.

Answer 41

Secondary peritonitis occurs from perforation of an abdominal organ. It is associated with signs of severe sepsis such as hypotension and tachycardia. Peritoneal signs such as rebound and guarding are common. THe ascitic fluid protein is elevated. This form of peritonitits must be treated with surgical repair in addition to antibiotics. Lok for air under the diaphragm on an upright CXR.

Question 42

A man comes in for evaluation of the recurrent peptic uclers are multiple, >2cm in size, and located in the distal portion of the duodenum. Treatment of Helicobacter pylori has resulted in no benefit. He also has diarrhea. What is the most likely diagnosis? What is the most accurate diagnostic test? What is the therapy?

Answer 42

Zollinger Ellison Syndrome (ZES) is the most likely diagnosis when the question describes a patient with ulcers that are large, distal, multiple, and recurrent after treatment for H Pylori. Most ulcers are <1cm in size. Diarrhea is from the inactivation of lipase. The most accurate diagnostic test is an elevated gastrin level when off H2 blockers or PPIs. Secretin should normally suppress gastrin. In Se, secretin causes a rise in gastrin levels. Local disease should be resected. Mets should be treated with lifelong PPI

Question 43

An elderly lam is brought to the ED with tachycardia, diaphoresis, palpitations, and lightehadedness that beigns 15 - 30 min after eating. He had surgery in the past for nonresolving ulcers. Another hour or two after eating symptoms recur. What is the most likely diagnosis? What is the therapy?

Answer 43

Dumping syndrome occurs int hose with vagotomy and gastrectomy as part of surgery for ulcer. There are two phases with similar symptoms. Initially there is a rapid release of gastric contents into the duodenum, resulting in an osmotic draw of fluids into the intestine that results in hypotension, lightheadedness, tachycardia, palpitations adn sweating. Later, there is a rapid release of insulin resulting in hypoglycemia, which produces many of the same symptoms.
Dumping syndrome is managed with multiple small meals devoid of simple carbs. Dumping syndrome is also seen int hose with morbid obesity that have undergone gastric bypass sx.

Question 44

A patient with longstanding diabetes comes to the office for evaluation of N&V, anorexia, with a sense of early satiety and abdominal “bloating.” Sometimes there is diarrhea, and sometimes constipation. WHat is the most likely diagnosis? WHat is the most accurate diagnostic test? What is the therapy?

Answer 44

Diabetic gastroparesis is a form of autonomic neuropathy occuring in patients with longstanding diabetes and its effect on the nerves of the stomach. THere is bloating with early satiety. The major stimulant to gastric motility is stretch. Longstanding diabetes results in a neurpathy that reduces the ability of the gastrointestinal tract to percieve stretch. Diagnosis is definitively determined with a nuclear gastric emptying study. Promotility agents such as metoclopramide and erythromycin will relieve symptoms.