GI Ddx (Pass NPLEX)

Question 1

What is the difference between laparoscopy and laparotomy?

Answer 1

Laparoscopy uses several small incisions often called “keyhole” incisions, one at the belly button and approx. 2 or more elsewhere, depending on what needs to be done. Since the incisions are smaller, healing time is shorter as well as the hospital stay.

Laparotomy is the traditional open abdominal surgery. Incision can be 4 inches. This method has a much longer recovery (6 to 8 weeks).

Question 2

Meckel’s Diverticulum may mimic the symptoms of what other condition?

Answer 2

Appendicitis.

Therefore during an appendectomy the ileum should be checked for the presence of Meckel’s diverticulum. If it is found to be present it should be removed along with the appendix.

Question 3

What is the keynote symptom/sign of an ileus?

Answer 3

Abdominal distention

Question 4

Why is a barium X Ray used in Crohn’s Disease?

Answer 4

A barium X-Ray can show where lesions are active in the small intestine that can’t easily be viewed

Question 5

Why does Lactose Intolerance often occur with Celiac Disease?

Answer 5

Lactase is produced within the villi, therefore if the villi are damaged there will be insufficient lactase enzyme

Question 6

What is a Volvulus?

Answer 6

Twisting of the intestines; often related to constipation or laxative abuse in adults

Question 7

What is Curling’s ulceration of the duodenum?

Answer 7

Severe stress (such as burns or bodily injuries) that causes shock. The hypotension (from shock) then leads to decreased gastric mucosal blood supply and a resultant ischemic ulcer forms

Question 8

What is the main investigation method for toxic megacolon?

Answer 8

Abdominal plain film repeated every 12-24 hours (because signs can fluctuate rapidly)

Question 9

What is a common sequela to ileal resection in Crohn’s Disease?

Answer 9

Urolithiasis

Question 10

What is Hirschsprung’s disease?

Answer 10

It is an autosomal dominant condition, in which the myenteric plexus does not develop. The affected segment of the colon fails to relax, causing an obstruction.

More common in boys than girls

Question 11

Why are Meckel’s diverticulum occasionally involved in peptic ulceration?

Answer 11

Meckel’s Diverticulum often have ectopic gastric (or pancreatic) tissue. The gastric tissue may increase HCl production and thereby lead to ulceration.

Question 12

Describe the Rule of 2s with respect to Meckel’s Diverticulum?

Answer 12

2% of population
2:1 male-to-female ratio
2% of cases are symptomatic
Found within 2 feet of the ileocecal valve
2 inches in length
2 ectopic types of tissue may be found (gastric or pancreatic)
present by age of 2

Question 13

What is adynamic ileus? etiology?

Answer 13

GI obstruction from motor dysfunction (there is NO physical block present)

Usually occurs in reaction to abdo surgery, hypothyroidism, spinal cord injury

Question 14

Are perianal skin tags more common in Crohn’s or Ulcerative Colitis?

Answer 14

Crohn’s disease (75% of cases

Question 15

What part of the GI tract is typically spared in toxic megacolon?

Answer 15

The rectum

Question 16

Crohn’s vs Ulcerative Colitis: Which condition is more likely to have fistula as a comorbidity?

Answer 16

Crohn’s Disease

a. ) Enterocutaneous (MC)
b. ) Enteroenteral
c. ) Enterovesicular (frequent UTIs)
d. ) Enterovaginal

Question 17

Is uveitis more common in Crohn’s or Ulcerative Colitis?

Answer 17

Crohn’s Disease

Question 18

Where is the most common location of diverticula?

Answer 18

In the sigmoid colon

Question 19

What is Meckel’s Diverticulum?

Answer 19

Meckel’s Diverticulum is a small out-pouching in the small intestine. It is remnant of the embryonic viteline duct

Question 20

Describe the pathophysiology behind Celiac Disease

Answer 20

Celiac disease is an auto-immune reaction that predispose a patient to an averse immunologic response in the presence of prolamines (high proline-containing proteins such as gliadin/gluten from wheat, rye, spelt, and barley).

Upon exposure to gliadin the enzyme tissue transglutaminase cross-links with gliadin/gluten that prompts a cross-reaction B-cell production of anti-tissue transglutaminase antibodies in individuals with variant HLA DQ2 & HLA DQ8. The antibodies then initiate an inflammatory cascade that leads to intestinal villous atrophy. The villous atrophy and truncation leads to a loss of surface area and gross nutrient malabsorption.

Question 21

What diarrheal cause has an abrupt onset of profusely watery diarrhea without pain or nausea/vomiting?

Answer 21

Cholera

Question 22

What bacterial food poisoning can inoculate in rice?

Answer 22

Bacillus cereus

Question 23

How do you confirm a salmonellosis diagnosis?

Answer 23

A Rise in serum O and H agglutinin titers 3-4 weeks post-infection

Question 24

Aside from diarrhea, what are the main symptoms of botulism?

Answer 24

1. ) Bilateral descending flaccid paralysis
2. ) Loss of Pupillary light reflex
3. ) Double vision or blurred vision
4. ) Eventual constipation

Question 25

MC cause of traveler's diarrhea?

Answer 25

Enterotoxigenic Echerichia coli (ETEC)

Question 26

What is Hemolytic Uremic Syndrome?

Answer 26

A triad of: 1. ) Hemolytic Anemia 2. ) Thrombocytopenia 3. ) Acute renal failure Related to EHEC, Shigella, or Staphylococcus gastrointestinal infection

Question 27

When do Sx of HUS start? What are the symptoms of hemolytic uremic syndrome?

Answer 27

The symptoms develop about 5-10 days after the onset of EHEC (Shiga-like toxin) diarrhea: 1. ) Thrombocytopenia (purpura, epistaxis, hemoptysis, GI bleeding) 2. ) Microangiopathic hemolytic anemia (MAHA) i. ) The endothelial layer of small vessels becomes damaged and results in fibrin deposition and platelet aggregation. Then as RBCs travel through the damaged blood vessels they are fragmented (into schistocytes) resulting in intravascular hemolysis. 3. ) Renal Failure (oliguria, hematuria)

Question 28

What are the different types of E coli?

Answer 28

1. ) Enterotoxigenic (ETEC) - produces enterotoxins and Traveller's diarrhea. There is no inflammation or invasion 2. ) Enteropathogenic (EPEC) - adheres to apical membrane and flattens villi resulting in decreased absorption. No toxin produced. Usually in children (P for pediatrics) 3. ) Enteroinvasive (EIEC) - plasmid mediated invasiveness that is similar to shigella. It causes dysentery. Necrosis and inflammation are present. 4. ) Enterohemorhagic (EHEC) - produces shiga-like toxin with dysentery and Hemolytic-uremic syndrome

Question 29

What is the most common viral cause of diarrhea?

Answer 29

Rotavirus

Question 30

What are the most concerning complications of botulism?

Answer 30

Aspiration pneumonia and respiratory failure

Question 31

In staphylococcal food poisoning, how will an investigative stool culture and gram stain come back?

Answer 31

Both the stool culture and gram stain will be negative because the food poisoning is toxin-mediated not pathogen mediated

Question 32

What is the most common bacterial cause of bloody diarrhea in USA?

Answer 32

Campylobacter jejuni

Question 33

What parasitic infection produces respiratory complaints such as a cough, dyspnea, and pulmonary infiltrates from larval migration?

Answer 33

Ascaris lumbricoides (roundworm)

Question 34

1.) What form of E.coli infectious diarrhea is accompanied by bloody diarrhea? 2.) What is the toxin found in this particular strain of E coli?

Answer 34

Enterohemorrhagic E.coli (EHEC) with Shiga-like toxin

Question 35

Why is botulism a greater concern in infants?

Answer 35

Clostridium botulinum spores are able to colonize in the colon of infants, whereas in adults the botulism experienced is solely from preformed toxin

Question 36

What parasitic infection is often associated with drinking water from streams while camping?

Answer 36

Giardia lamblia

Question 37

How can you rule out Guillain-Barre Syndrome in the investigation of Botulism?

Answer 37

Electromyography

Question 38

Which parasite is hallmarked by nocturnal rectal pruritis?

Answer 38

Enterobius vermicularis (pinworm)

Question 39

What are the 4 most common viral causes of diarrhea?

Answer 39

``` Norwalk Virus Adenovirus Rotavirus Calci Virus Mnemonic: NARC ```

Question 40

What food poisoning may present similarly to appendicitis?

Answer 40

Yersinia enterocolitica

Question 41

Shigellosis vs Salmonellosis: Which requires a very small inoculum concentration?

Answer 41

Shigellosis requires a very small inoculum concentration (it is very contagious) Salmonellosis requires a large inoculum concentration

Question 42

What toxin is associated with hemolytic uremic syndrome?

Answer 42

Shiga toxin generally from EHEC and sometimes from Shigella or Campylobacter

Question 43

What are the main signs and symptoms of typhoid fever?

Answer 43

1. ) Rose spots on the abdomen 2. ) Fever 3. ) Headaches 4. ) Diarrhea

Question 44

What parasitic infection is identified using the scotch tape test?

Answer 44

Enterobius vermicularis because the pinworms lay eggs at night around the rectal sphincter

Question 45

Hookworms (Necator americanus & Ancylostoma duodenale) may cause what extra-intestinal condition?

Answer 45

Anemia

Question 46

What bacteria can cause Reactive Arthritis? What are the symptoms of reactive arthritis?

Answer 46

Salmonella, Shigella, Campylobacter, Chlamydia, Streptococcus (post-streptococcal reactive arthritis), Yersinia Symptoms = Uveitis, Urethritis, Arthritis Mnemonic: Can't See, Can't Pee, Can't Climb a Tree

Question 47

Hepatocellular carcinoma can stem from what condition?

Answer 47

Liver cirrhosis

Question 48

What is the incubation period for Hepatitis A Virus?

Answer 48

30 days (average) 2-6 weeks

Question 49

What are your main DDxs for hepatomegally?

Answer 49

1.) Congestive (Right) Heart Failure 2. ) Infiltrative i. ) Malignancy (leukemia, hepatocarcinoma) ii. ) Benign (fatty liver, cysts, hemochromatosis, amyloidosis) 3. ) Proliferative i. ) Infectious/Inflammatory (viral, TB, abcess, granulomas)

Question 50

What are the 2 major complications associated with hereditary hemochromatosis?

Answer 50

1. ) Liver cirrhosis | 2. ) Pancreatic Failure resulting in diabetes

Question 51

Caput medusae occurs in what condition?

Answer 51

Liver cirrhosis. Caput medusae is the appearance of distended and engorged paraumbilical veins

Question 52

What percent of patients with Hepatitis C develop cirrhosis or hepatocarcinoma?

Answer 52

20%

Question 53

What do interferons do?

Answer 53

They interfere with viruses IFN alpha + beta inhibit viral protein synthesis by inducing the production of ribonuclease which degrades the mRNA of the virus IFN gamma increases MHC 1 and 2 expression

Question 54

What is Primary Sclerosing Cholangitis?

Answer 54

The inflammation (cholangitis) and scarring (sclerosing) of the bile ducts either in the liver (intrahepatic) or extrahepatically. The scarring impedes bile flow (cholestasis) and results in liver cirrhosis, liver cancer, and liver failure.

Question 55

Hepatomegally is present at what stage of alcoholic hepatitis?

Answer 55

Early on. In later stages of hepatitis the liver shrinks.

Question 56

1. ) What does AST do? | 2. ) Where is it found?

Answer 56

1.) Aspartate Transaminase catalyzes the interconversion of aspartate and a-ketoglutarate to oxaloacetate and glutamate. Aspartate (Asp) + a-ketoglutarate ? oxaloacetate + glutamate (Glu) 2.) Found in cardiac tissue, liver, skeletal muscle, RBCs

Question 57

What should the practitioner screen for in patients with unexplained NASH?

Answer 57

1. ) Diabetes & Insulin Resistance | 2. ) Hemochromatosis

Question 58

What are the causes of biliary tract obstructions?

Answer 58

1. ) Gall stones 2. ) Cancer 3. ) Hemobilia - occurs when there is a fistula between the splanchnic circulation and the hepatic biliary system 4. ) Sclerosing cholangitis

Question 59

What are the 3 major types of Jaundice?

Answer 59

1. ) Hemolytic = the breakdown of red blood cells 2. ) Hepatic = the excretion of bile is impaired due to dysfunctional hepatocytes 3. ) Cholestatic = obstruction of the bile duct prevents the successful excretion of bile

Question 60

What is Charcot's triad?

Answer 60

1. ) RUQ pain 2. ) Fever 3. ) Jaundice The three most common symptoms in cholangitis (bacterial infection of gallbladder that requires emergency antibiotics and/or surgery)

Question 61

What population group is at the greatest risk of hereditary hemochromatosis?

Answer 61

Celtic, British, and Sacndinavian people

Question 62

What is the cause of primary sclerosing cholangitis?

Answer 62

It is thought to be autoimmune; more than 80% of cases occur in patients with ulcerative colitis.

Question 63

What are the main risk factors associated with chronic pancreatitis?

Answer 63

1. ) Alcoholism 2. ) Hypercalcemia (rare) 3. ) Pancreatic Cancer 3. ) Cholelithiasis that is obstructing the pancreatic duct

Question 64

H. Pylori infected gastritis most commonly affects what part of the stomach?

Answer 64

The antrum

Question 65

Describe the difference between Type-A and Type-B Gastritis

Answer 65

Type-A Gastritis (causing pernicious anemia) = autoimmune antibodies against parietal cells leading to achlorhyrdia and a decrease in Intrinsic Factor Type-B Gastritis (from H.pylori) a.) Other causes = NSAIDs, alcohol, smoking, elderly, stress

Question 66

What is Zollinger-Ellison Syndrome?

Answer 66

Triad of: 1. ) Gastrinoma tumour in the pancreas or duodenum, causing: 2. ) Gastric acid hypersecretion , causing: 3. ) Severe peptic ulceration

Question 67

If you have an esophageal condition resulting in dysphagia and iron deficiency, what is the most likely diagnosis?

Answer 67

Plummer-Vinson Syndrome that results in upper esophageal webs, iron deficiency, glossitis, and cheilosis

Question 68

Esophageal webs are most commonly associated with what condition?

Answer 68

Plummer-Vinson Syndrome Marked by: esophageal webs, iron deficiency, cheilosis/angular stomatitis (dry scaling lips), and glossitis. The condition typically occurs in middle-aged females

Question 69

What are the 3 most common causes of Parotiditis?

Answer 69

1. ) Mumps virus 2. ) S.aureus (suppurative parotiditis) 3. ) Sjorgren's disease

Question 70

Plummer-Vinson Syndrome increases the risk of what cancer?

Answer 70

Post-cricoid Cancer

Question 71

What is Barrett's Esophagus?

Answer 71

The metaplastic change of stratified squamous cells in the lower esophagus to columnar epithelia normally found in the lower GIT This can result in esophageal stricture, ulceration, or cancer

Question 72

Diverticulum in the oropharynx just above the cricopharyngeal muscle (above the upper esophageal sphincter) is called?

Answer 72

Zenker's Diverticulum

Question 73

If you have an esophageal condition resulting in dysphagia that is made worse by anxiety, what is the most likely diagnosis? How would you evaluate it?

Answer 73

Globus sensation All evaluations will come back negative because there is no organic pathology.

Question 74

What is Esophageal Atresia?

Answer 74

A congenital condition where the esophagus ends in a blind-ended pouch rather than connecting normally to the stomach. It often results in fistula with the trachea

Question 75

What is Zenker's Diverticulum?

Answer 75

It is a herniation/out-pouching of the esophagus generally at Killian's trinagle (the point of least resistance) in the proximal posterior esophagus that occurs because of increased traction and pulsation mechanisms of the esophagus.

Question 76

What are the main symptoms of Zenker's Diverticulum?

Answer 76

1. ) Dysphagia a. ) < supine (b/c the diverticulum is posterior) 2. ) Regurgitation of food & halitosis 3. ) Sometimes a cough (d/t aspiration)

Question 77

1. ) What is achalasia? | 2. ) What are the complications?

Answer 77

1. ) The loss of lower esophageal motility, causing an inability to relax the LES. This results in an enlarged esophageal lumen with chronic food stasis 2. ) Complications = aspiration pneumonia and esophageal cancer

Question 78

What would your management plan for Plummer-Vinson's esophageal webs be?

Answer 78

Refer to a gastroenterologist

Question 79

What is the difference between a true and false diverticulum?

Answer 79

True Diverticulum is the outpouching of the colon wall (typically located in the sigmoid) that contains all layers, including the muscularis and adventitial layers. True Diverticulum are congenital and typically occur on the right side. False Diverticulum (Pseudodiverticulum) is the outpouching of the colon wall that only contains the mucosal and submucosal layers. It is acquired and typically increases in incidence with age (>40 yoa). Generally located on the left side

Question 80

What are the main interventions for diverticulosis?

Answer 80

1. ) High Fiber Diet 2. ) Avoid Seeds/nuts 3. ) Probiotics 4. ) Castor Oil Packs & Avoid Constipation a. ) Constipation increases colonic pressure and may worsen any herniated colonic tissue 5. ) Weight Loss & Exercise

Question 81

What are the 4 degrees of Internal Hemorrhoids?

Answer 81

First Degree - no prolapse Second Degree - prolapses during defecation but reduces spontaneously Third Degree - prolapses and requires manual correction Fourth Degree - Prolapses out of anus and is not reducible

Question 82

What are the main risk factors for Toxic Megacolon?

Answer 82

Risk Factors: i. ) IBD (Crohn's & Ulcerative Colitis) ii. ) Pseudomembranous colitis iii. ) antimotility drug use iv. ) HIV infection

Question 83

What are the two shapes of colorectal polyps?

Answer 83

Sesile (flat) & Pedunculated (on a stalk)

Question 84

Compare and contrast Tubular (Pedunculated) and Villous (Sessile) Polyps: 1. ) Incidence rate 2. ) Size 3. ) Malignant Potential 4. ) Distribution

Answer 84

1. ) Tubular polyps are more common (60-80%) whereas villous polyps are less common (10%) 2. ) Tubular polyps are small (<2cm) while Villous polyps are large (>2cm) 3.) Tubular polyps have a low malignancy potential. Villous polyps infer a high malignancy risk. Note: the larger the polyp, the greater the cancer risk 4.) Villous polyps typically occur on the left side. Tubular polyps are evenly distributed

Question 85

Rubber band ligation of hemorrhoids. Is it performed on internal or external hemorrhoids?

Answer 85

Internal hemorrhoids of any grade.

Question 86

What part of the GI tract is typically spared in toxic megacolon?

Answer 86

The rectum.