High Yield Topics-GI Flashcards
Difficulty initiating swallowing with cough and choking is likely _______ dysphagia
oropharyngeal
Dysphagia with solids progressing to liquids is likely due to
mechanical obstruction
stricture, carcinoma
For mechanical obstruction dysphagia, what is the work-up for a patient WITHOUT history of prior radiation, caustic injury, complex stricture, or esophageal/laryngeal cancer surgery?
Upper endoscopy
For mechanical obstruction dysphagia, what is the work-up for a patient WITH history of prior radiation, caustic injury, complex stricture, or esophageal/laryngeal cancer surgery?
Barium swallow +/- upper endoscopy
Dysphagia with solids & liquids at onset is likely due to
motility disorder (neuromuscular)
scleroderma, achalasia, diffuse esophageal spasm
For motility disorder, what is the work-up?
Barium swallow +/- manometry
A disease caused by failure of LES to relax due to loss of inhibitory neurons (contains NO and VIP) in the myenteric (Auerbach) plexus of the esophageal wall; associated with esophageal cancer
Achalasia
Describe manometry in achalasia
Absent peristalsis in the mid esophagus + high LES resting pressure (hypertonic)
Describe barium swallow in achalasia
dilated esophagus with distal stenosis (“bird’s beak)
A disease that is caused by a chronic infection by Trypanosoma cruzi –> secondary achalasia due to destruction of the submucosal (Meissner) and myenteric (Auerbach) plexus
Chagas disease
Tx and it’s MOA for achalasia
Tx: Botox
MOA: Prevents “Ach release” by binding presynaptically –> inhibition of Ach-nergic neurons and LES relaxation
- think about C. Botulism toxin’s MOA = same
An esophageal disorder characterized by “periodic”, non-peristaltic contractions of the esophagus + normal LES pressure due to impaired inhibitory innervation of myenteric plexus; presents with dysphagia + chest pain due to inefficient propulsion of food into the stomach
Diffuse esophageal spasm
Describe barium swallow and manometry in Diffuse esophageal spasm
- Barium Swallow: “corkscrew” esophagus
- Manometry: Simultaneous multi-peak contractions on manometry
Tx for Diffuse esophageal spasm
Nitrates and CCBs
A Th2 cell-mediated disorder leading to eosinophilic infiltration in the esophagus; most common in atopic patients (food allergy); presents w/ solid dysphagia, reflux, and food impaction that doesn’t respond to GERD therapy
Eosinophilic esophagitis
An esophageal disorder caused by pathogens or pill-induced (pill being stuck –> damage esophagus)
Esophagitis
Describe each pathogen’s related endoscopic finding of infectious esophagitis in immunocompromised patients.
HSV
Candida
CMV
- HSV : punched-out ulcers
- Candida : white pseudomembrane (look like thrush in esophagus)
- CMV : linear ulcers
Describe histology of HSV/CMV induced esophagitis
Enlarged multinucleated cells with intranuclear inclusions
caused primarily by LES incompetence –> acidic gastric contents irritate the esophageal mucosa; presents as heartburn, regurgitation, dysphagia; may also present as chronic cough and hoarseness
Gastroesophageal reflux disease
Histology finding of GERD
basal zone layer hyperplasia, elongation of the lamina propria papillae, and scattered eosinophils
Tx for GERD
H2 receptor antagonists (ranitidine) or PPIs
pantoprazole, omeprazole
MOA of PPIs
MOA of H2 receptor blockers
- irreversibly inhibit the H+/K+ ATPase on parietal cells –> ↓ gastric acid secretion
- block the action of histamine at the histamine H₂ receptors of the parietal cells –> ↓ gastric acid secretion
Minerals salts that are often used as tx for GERD
calcium carbonate
magnesium carbonate
aluminum hydroxide (Al-OH) magnesium-OH
Why are magnesium-OH and Al-OH often prescribed in combo?
to offset their side effect in individual prescription.
- magnesium OH: diarrhea
- aluminum hydroxide (Al-OH): constipation
- STUDY AID: “M”agnesium causes “M”essy stool (diarrhea)
What elevated hormones in pregnant women cause GERD by relaxing the LES smooth muscle?
Estrogen and progesterone
a hole/rupture in the esophagus that allows saliva, liquids, and food to spill into the thoracic cavity or abdomen; most commonly due to iatrogenic reason (endoscopy or instrument perforates the esophagus during procedure); may present with pneumomediastium (air in mediastinum)
Esophageal perforation
Distal esophageal rupture due to violent retching and presents with pneumomediastinum (air in mediastinum); transmural (all esophagus layers) rupture
Boerhaave syndrome
Dilated submucosal veins in lower esophagus due to “portal” hypertension (caused by cirrhosis); presents with hematemesis (vomiting blood)
esophageal varices
Tear of LES (gastroesophageal junction); It typically results from repetitive forceful vomiting, which can also cause meta alkalosis; presents with hematemesis in alcoholics and bulimics; only mucosal or submucosal rupture (therefore no pneumomediastinum)
Mallory Weiss syndrome
Triad of Dysphagia, Iron deficiency anemia, Esophageal webs; increased risk of esophageal Squamous cell carcinoma
Plummer-Vinson syndrome
- “When I Diarrhea, I need a plumber”
An esophageal disorder that present with dysphagia caused by rings formed at gastroesophageal junction, typically due to chronic acid reflux.
Schatzki rings
An esophageal disorder caused by systemic sclerosis–> esophageal smooth muscle atrophy and decreased LES pressure and dysmotility of esophagus; presents with GERD or dysphagia; Part of CREST syndrome (Limited scleroderma)
Sclerodermal esophageal dysmotility
Sclerodermal esophageal dysmotility can increase risk of what two esophageal pathologies?
barrett esophagus
stricture formation
- due to decreased LES pressure causing acid reflux
Metaplastic condition in which the normal “squamous” epithelium of the distal esophagus is replaced by intestinal-type COLUMNAR epithelium. It occurs most often in longstanding acid reflux and is associated with an increased risk of adenocarcinoma
Barrett esophagus
Histology findings in Barrett esophagus
Normal “squamous” epithelium of the distal esophagus is replaced by intestinal-type COLUMNAR epithelium; stains blue due to goblet cells (normally not present in esophagus)
Presents with progressive dysphagia (solids –> liquids) and weight loss; Aggressive course (rapid extension) due to lack of serosa; poor prognosis
Esophageal cancer
A type of esophageal cancer that affects upper 2/3 esophagus; risk factors include alcohol, smoking, hot liquids, achalasia
squamous cell carcinoma
- think about squamous cells (protective) for the upper 2/3
A type of esophageal cancer that affects lower 1/3 esophagus; risk factors include GERD, Barrett esophagus, obesity, smoking, and achalasia
adenocarcinoma
- think about acid secreting glands (adeno) for the lower 1/3
What peptic ulcer is associated with pain that increases with meals, weight loss, and increased risk for gastric carcinoma?
gastric ulcer
Most common site of gastric ulcer
antrum of the stomach (lesser curvature side)
Why it is required to biopsy MARGINS of gastric ulcer?
to rule out malignancy (Irregular borders is highly suggestive of malignancy)
The most common reason for gastric ulcer
H. Pylori and NSAIDs (inhibits prostaglandin) –> decrease mucosal protection against gastric acid
What peptic ulcer is associated with pain that decreases with meals, weight gain, and benign intestinal cancer?
Duodenal ulcer
Most common site of Duodenal ulcer
posterior > anterior
The most common reason for Duodenal ulcer
H. Pylori and Zollinger-Ellison syndrome
Gastrin-secreting tumor (gastrinoma) of pancreas, stomach, or duodenum; associated with MEN 1 (PPP); often presents with several peptic ulcers (esp. in unusual locations)
Zollinger-Ellison syndrome
Zollinger-Ellison syndrome is positive for what tests (2)?
- Fasting serum gastrin level
* gastrin levels is high in absence of trigger (food) - secreting stimulation test
* gastrin levels remain high after secretin (inhibits gastrin release) administration due to ectopic release of gastrin
If a gastric peptic ulcer on the LESSER curvature ruptures, bleeding occurs from what artery?
Left Gastric Artery
If a duodenal peptic ulcer on the posterior wall ruptures, bleeding occurs from what artery?
Gastroduodenal artery
Which type of peptic ulcer (duodenal vs. gastric) is associated with higher incidence due to “H. Pylori”
Duodenal ulcer (90% of cases)
*Gastric is 70%
Which type of peptic ulcer is associated with the HIGHEST risk of perforation and cause pneumoperitoneum (air under diaphragm) with referred pain to the shoulder (referred from phrenic nerve)?
Anterior Duodenal Ulcer
Drug with reversible block of H2-receptors (histamine) –> decrease H+ secretion by parietal cells; tx for peptic ulcer, gastritis, and GERD
H2 blockers (-tidine)
Cimetidine, ranitidine, famotidine, nizatidine
What H2 blocker inhibits cytochrome p-450 –> multiple drug interactions?
Cimetidine
What H2 blocker has antiandrogenic effects –> prolactin release, gynecomastia, decreased libido)
Cimetidine
Drug that IRREVERSIBLY inhibit H+/K+ ATPase in parietal cells –> decrease H+ secretion; tx for peptic ulcer, gastritis, and GERD
PPIs (-prazole)
omeprazole, lansoprazole, pantoprazole
What drug increases the risk of C. diff infection?
PPIs
What drug decreases Mg+2 and Ca+2 absorption –> increased fracture risk in elderly?
PPIs
Drug that provides physical protection and allows HCO3- secretion; tx for peptic ulcer, traveler’s diarrhea
Sucralfate
Bismuth
Drug that prevents NSAID-induced peptic ulcers; also used for abortion so contraindicated in pregnancy
Misoprostol
MOA of misoprostol
PGE1 (prostaglandin) analog –> protects against NSAIDs (inhibits PGE1 production)
- PGE1 causes myometrial cells of uterus to contract
Drug that alters gastric and urinary pH; can cause hypokalemia, constipation, and hypophosphatemia
Antacids
CaCO3
Mg(OH)2
CaCO3 overused can cause what hypercalcemia disorder?
Milk-alkali syndrome
Infection with Tropheryma whipplei (intracellular gram ⊕) –> cardiac, arthralgia, and neurologic symptoms –> steatorrhea
Whipple disease
- STUDY AID: Pixorize
- heart shaped sofa
- helmet
- spiky knee protector
- exposed gold butt
Histologic findings in Whipple disease
PAS⊕ foamy macrophages in intestinal “lamina propria”
- STUDY AID: Pixorize
- pink (PAS+) foam in cage
Gluten-sensitive enteropathy caused by autoimmune-mediated intolerance of gliadin leading to malabsorption (iron, Ca+2, vitamin D/A/K, fat/protein), “steatorrhea”, and iron deficiency anemia
Celiac disease
Celiac disease is also associated with what other findings?
- bone
- skin
- Immunodeficiency
- ↓ bone density
- dermatitis herpetiformis (rash that appears on knee/elbows usually)
- selective IgA deficiency
Antibodies associated with celiac disease (3)
- IgA anti-tissue transglutaminase (IgA tTG)
- anti-endomysial
- anti-gliadin
Histologic findings of Celiac disease
- KNOW THIS COLD!
- Villous atrophy (flattened)
- Crypt hyperplasia
- Intraepithelial lymphocytosis (autoimmune disease)
Celiac disease increases risk for what cancer?
T-cell lymphoma
Site most affected by celiac disease
distal duodenum or proximal jejunum
A test that measures the level of D-xylose (sugar) in a blood or urine sample; absorption of D-xylose requires INTACT intestinal mucosa —> decreased absorption (decreased level in urine or blood) means mucosa defects (celiac disease)
D-xylose Test
Tx for Celiac disease
gluten free diet
Pancreatic insufficiency will have ___ D-xylose test
normal/negative
What stain is used to test for fecal fat (steatorrhea)?
Sudan stain
An enteropathy that present very similar to celiac disease but RESPONDS to antibiotics; “unknown” cause but common in patients who recently traveled to tropics
Tropical sprue
True diverticulum (all layers including muscular layer) caused by persistence of the vitelline (omphalomesenteric) duct; most common congenital anomaly of GI tract; present with blood in rectum/stool and resultant microcytic anemia (due to iron deficiency) in young children/infants
Meckel diverticulum
What causes blood in rectum/stool in Meckel diverticulum?
Ectopic gastric mucosa (or pancreas) in diverticulum –> HCl secretion –> ulcers –> bleeding
Meckel diverticulum is differernt from omphalomesenteric cyst which is a
cystic dilation of vitelline duct
What is used to diagnose Meckel diverticulum?
99mTc-pertechnetate scan
+ if uptake by ectopic gastric mucosa
The rule of 2’s for Meckel diverticulum
**2 times as likely in males
**2 inches long
**2 feet from the ileocecal valve
**2% of population
Hemorrhoids that occur above pectinate line
Internal hemorrhoids
What type of cancer can occur above pectinate line?
Adenocarcinoma
Hemorrhoids that occur below pectinate line
External hemorrhoids
What type of cancer can occur below pectinate line?
squamous cell carcinoma
*think about external (squamous) side
Which type of hemorrhoids are not painful and why?
Internal hemorrhoids b/c of VISCERAL innervation
Which type of hemorrhoids are painful and why?
External hemorrhoids b/c of SOMATIC innervation
Nerve that innervates external hemorrhoids and cause pain
Inferior rectal branch of pudendal nerve
Tear in anal mucosa BELOW pectinate line; presents with pain (pudendal nerve) and blood
anal fissure