Introduction to Gastroenterology Flashcards
List some GI alarm symptoms
Anemia
dysphagia
Odynophagia
Hematemesis
Melena/hematochezia
Unintentional weight loss
Recurrent vomiting
Abdominal mass
Jaundice
Anorexia
steatorrhea
A vague, intensely disagreeable sensation of sickness or “queasiness” with or without vomiting
Nausea
The forceful expulsion of gastric contents through a relaxed upper esophageal sphincter and open mouth
Coordinated gastric, abdominal, and thoracic contractions
Vomiting
What are the stimulators of vomiting?
Gastrointestinal Viscera
Vestibular system
Higher CNS centers (cortex and limbic system)
“Chemoreceptor trigger zone”
List some causes of vomiting
Food poisoning
Gastroenteritis
Drug reactions
Vestibular responses
Systemic illness
Peritoneal irritation
Obstruction
Gastric stasis
Pancreatic disease
Biliary disease
Pregnancy
Gastric outlet obstruction
Gastroparesis
Intestinal dysmotility
Psychogenesis
CNS or systemic disorders
What are some complications of vomiting?
Dehydration
Pulmonary aspiration
Metabolic disturbances - Hypokalemia, Metabolic alkalosis
Azotemia secondary to loss of gastric contents
Boerhaave’s syndrome
Mallory-Weiss tear
What is the treatment for vomiting?
Treat the underlying cause!
Most cases of acute vomiting are mild and self limiting
Symptomatic treatment - Clear oral fluids, Small feedings
Antiemetics can be given to treat or prevent vomiting - Ondansetron (Zofran), Promethazine (Phenergan)
Severe, acute vomiting may require hospitalization - IV fluids, metabolic disturbances corrected
Term used to describe upper abdominal symptoms - Persistent or recurrent pain or discomfort centered in the upper abdomen
Synonymous with indigestion
Characterized by: Early satiety, Postprandial fullness
Dyspepsia
List some causes of dyspepsia
Food Intolerance
Drug Intolerance
Infection
Gastric Tract Dysfunction
What type of dyspepsia is described below?
Patients tend to be younger
Have a variety of abdominal and GI symptoms
Increased incidence of anxiety or depression
Non-Ulcer Dyspepsia
What type of dyspepsia is described below?
Patient typically older (>55)
Often smoke and consume alcohol
Pain is changed with food or meals
Ulcer Dyspepsia
A perception of abnormal bowel movements
Hard stools, Straining, Decreased frequency, Feeling of incomplete evacuation
Typically increased in older patients and women
One of the most common complaints seen by PCPs and gastroenterologists
Constipation
What is the medical criteria for constipation?
<3 bowel movements per week and/or excessive straining with defecation
Constipation is associated with what factors?
Medications
Sedentary lifestyle
Poor caloric intake
Low fiber diet
List some causes of constipation
Diet (most common cause)
Medications
Structural abnormalities
Cystic Fibrosis
Systemic endocrine disorders
Slow colonic transport
Pelvic floor dysfunction
Irritable Bowel Syndrome
Colonic atony/dysmotility
MC in kids – function constipation (act of intentionally withholding bowel movement)
What is the most common cause of constipation?
Diet (most common cause)
What is the most common cause of constipation in children?
function constipation (act of intentionally withholding bowel movement)
What are some treatment options for constipation?
Dietary Measures - High fiber diet (25g per day), Reinforce importance of fluid and exercise
Bulking agents
Osmotic laxatives
Stool Surfactants
Chloride secretory agents
Opioid-Receptor Antagonists
Stimulant Laxatives (cathartic)
Biofeedback/manometry for neurogenic causes
Stop offending medication
Get immobile patient moving
Nonabsorbable osmotic agents that increase secretion of water into intestinal lumen, softening stools and promoting defecation
Osmotic laxatives
Enables water and fats to be incorporated into the stool
Stool Surfactants
Stimulate intestinal chloride secretion through activation of chloride channels or guanycyclase C causing increased intestinal fluid and colonic transit
Chloride secretory agents
Stimulate fluid secretion and colonic contraction
Stimulant Laxatives (cathartic)
Chronic use of these agents may result in loss of normal colonic neuromuscular function
Stimulant Laxatives (cathartic)
What are some treatment options for constipation in pediatrics?
Hydration
Increase dietary fiber
Decrease dairy products
Karo syrup
Bowel training
Medications - Softeners (after age 1), laxatives, enemas (premeasured in pedi size)
Referral - concerning findings or conservative treatment unsuccessful
Complication of stimulant laxatives
The most common cause of this condition is stimulant laxatives
(such as Senna)
Benign condition, not cancerous
Does not become cancerous
Melanosis Coli
What is the most common cause of Melanosis Coli?
stimulant laxatives
Severe impaction of stool may result in obstruction
Fecal Impaction
What are some predisposing factors of fecal impaction?
Severe psychiatric disease
Bedridden
Medications
Neurogenic disease of colon/spine
What are some treatment options for fecal impaction?
Short term: Impaction relief (DRE, Enemas, Disimpaction)
Long term: aimed at keeping stools soft and regular
Prevention:
Gastrocolic reflex – 30 minutes after eating breakfast
Avoid prolonged bathroom sessions
Regular bowel schedule
What methods are used to evaluate fecal impaction?
DRE
Radiograph
Air Contrast Barium Enema
Fecal impaction in children – having wet stools, but they’re impacted
Watery part is leaking out
Unable to sense the need to defecate because of stretching internal
sphincter by the retained fecal mass
Encopresis
What is the most common cause of Encopresis?
Most common cause is constipation, sometimes by fear of toilet/potty training (fecal withholding)
What is the clinical presentation of encopresis?
Daytime or nighttime soiling
Repeated passage of stool in inappropriate places (poop in their pants)
Child will soil their pants down their backs and legs
What are the treatment options for encopresis?
Treat the constipation
Educate for behavioral strategies
Enema for clean out
Miralax or pedialax to soften stool
Treat underlying disorder if applicable
Involuntary or voluntary release of gas from the stomach or esophagus
Normal physiologic reflex and does not indicate GI pathology
Eructation (Belching)
Normal volumes range from 500 to 1500mL/day
Frequency: 6-20 times a day
Sources/Causese: Swallowed air, bacterial fermentation of undigested
carbohydrates (increased fiber), malabsorption, lactase deficiency
Flatus
Definition: increased stool frequency >3 BM/day, or liquidity of feces
Varies from a self-limited annoyance to a severe, life threatening
illness
Patients may use this term to refer to:
Increased frequency of bowel movements
Increased stool liquidity
Sense of fecal urgency
Fecal incontinence
Diarrhea
What is the definition of acute diarrhea?
Acute is less than 3-4 weeks
What are the mechanisms of diarrhea?
Osmotic
Secretory
Malabsorptive
Exudative
Increased intestinal motility
In what percentage of cases, the course of acute diarrhea is mild and
self-limited lasting 5 days or less?
90%
Pre-liver bilirubin 🡪 conjugated in the liver
Not water soluble, therefore no bilirubin in urine
Stool and urine color normal
Typically mild jaundice
Unconjugated Bilirubinemia (Indirect)
What are the two main causes of unconjugated bilirubinemia (Indirect)?
Hemolysis (hemolytic anemias)
Inherited – Gilbert’s disease, Crigler-Najjar
Dark urine with jaundice
Light colored stools if obstruction
Conjugated Bilirubinemia (Direct)
What are some causes of Conjugated Bilirubinemia (Direct)?
Hepatocellular dysfunction
Biliary obstruction – most common cause
Inherited: Dubin-Johnson syndrome- rare, benign condition seen in pregnancy, EtOH, OCP use
Viral
Metabolic
Biliary tract disease
Vascular
Autoimmune liver disease
Hepatotoxins
What is the most sensitive test for synthetic liver function is what?
the PT
List some worrisome symptoms in hyperbilirubinemia
Onset of hepatic encephalopathy
Vitamin K resistant prolongation of PT
Cerebral edema
Bili > 18
Rising serum creatinine
Rising serum bilirubin with decreasing AST/ALT
Rising serum creatinine
Hypoglycemia
Sepsis
Ascites
pH <7.3 in acetaminophen overdose
Caused by hyperbilirubinema
Can be caused by ABO incompatibility or Rh incompatibility
Yellowing of skin, eyes, and mucus membranes
Jaundice
Irritation of phrenic or vagus nerve
Hiccups
Definition: bleeding that occurs below the Ligament of Treitz
Lower GI Bleed
What are the four major zones of the stomach?
Cardia
Fundus
Corpus
Antrum
Gastric acid secretion by parietal cells of the gastric mucosa is
controlled by what?
ACh – increases acid; muscarinic receptor M1
Histamine – increases acid; H2 receptor
Gastrin – increases acid
Prostaglandins E2 and I2 – decrease acid
Gastric juices are combined secretions of what?
Mucous cells: mucus
Parietal cells: HCl, Intrinsic factor
Chief cells: Pepsinogen I, Pepsinogen II
What do parietal cells secrete?
HCl, Intrinsic factor
What do chief cells secrete?
Pepsinogen I, Pepsinogen II
What hormone is described below?
secreted by G cells
In response to food entry
Increases stomach motility
primary mediator of gastric acid secretion
Promotes increased constriction of LES
Gastrin
What hormone is described below?
Secreted by I cells of jejunum
In response to fatty substances
Increases gallbladder contractility 🡪 bile
Stimulates pancreatic secretion
Regulates gastric emptying and bowel motility
Induces satiety
Cholecystokinin
What hormone is described below?
Produced by duodenal mucosa
With entry of gastric juice from the stomach
Stimulates pancreatic fluid/bicarb secretion (Neutralizes the acidity of stomach contents)
Secretin
What hormone is described below?
Peptide
Increases appetite
Stimulates GH secretion
Produces weight gain
Ghrelin
Starts at the dentate line - Ends at the anal verge
Junction of anal mucosa and perianal skin
Anal Canal
Circular muscle
Involuntary muscle
Contracted at rest
Internal sphincter of the anus
Voluntary striated muscle of the anus
External sphincter
What is the anorectal function?
Stores and releases intestinal waste products (Holds 650-1200mL of waste)
Hemorrhoid plexus - Maintain continence and minimize trauma during bowel movements
Progressive distension of the rectum will cause continuous inhibition of the internal sphincter and relaxation of external sphincter 🡪 urge to defecate
Majority of the liver is made up of what type of cells?
hepatocytes
The liver has a dual blood supply. Name to two sources and what percentage is attributed to each?
20% from the hepatic artery
80% from the portal vein
What is the function and importance of the hepatocytes?
Important I the synthesis of many important serum proteins, hormonal
factors, and growth factors
Involved in the regulation of nutrients, production of bile and its carriers, conjugation of bilirubin, and the detox of drugs for excretion
What is the function of bile?
Facilitates digestion: emulsification, absorption of fat (via micelles), solubilize cholesterol
Breakdown product of hemoglobin metabolism
direct (conjugated): water soluble
Indirect (unconjugated): lipid soluble
Bilirubin
What percentage of serum bilirubin is unconjugated in healthy adults?
90% of serum bilirubin
Bile secretion is controlled by what two factors?
Parasympathetic stimulation via vagus
Hormonal stimulation
These two enzymes together are collectively referred to as transaminases
AST and ALT
LFTs are markers of what?
markers of injury
Albumin, Coagulation factors, and conjugation of bilirubin are markers of what?
markers of liver function
Elevated in hepatocellular inflammation or destruction/necrosis
LFTs
Indicator of hepatic excretion
Bilirubin
Marker of the liver’s continued ability to synthesize important proteins
Albumin
Production increases with hepatic injury, obstruction, bone destruction
Alkaline phosphatase
These enzymes make up the LFTs
AST
ALT
LDH
List some common causes of LFT elevations
NAFLD
Toxins
Viral
List some uncommon causes of LFT elevations
Liver cancer
rhabdomyolysis
The pancreaticobiliary system is composed of what?
Gallbladder
Cystic duct
Ducts
Distensible sac - 30-50mL that concentrates and stores bile
Gallbladder
Formed in the liver
Modified and stored in the gallbladder, bile ducts
Emulsifies lipids
Transports wastes
Bile
Retroperitoneal gland 12-15cm long
Posterior to stomach
Consists of head, central body, and tail
Pancreas
What percentage of exocrine and endocrine cells make up the pancreas?
99% exocrine acini cells
1% endocrine islets cells
Pancreatic duct joins common bile duct which forms the what?
hepatopancreatic ampulla of Vater
The hepatopancreatic ampulla of Vater empties into the duodenum at what landmark?
major duodenal papilla
The major duodenal papilla is controlled by what?
Sphincter of Oddi
The list pancreatic secretions
Amylase
Lipase
Deoxyribonuclease and ribonuclease
Sodium bicarbonate
Proteases
Muscular tube connecting the oropharynx to the stomach
Begins at the level of the cricoid cartilage
Approximately 25cm long
Internal circular and external longitudinal layers of muscle
Esophagus
The esophagus has three constrictions where adjacent structures produce impressions, name them
Cervical constriction: Upper esophageal sphincter
Thoracic constriction: First crossed by the arch of the aorta then where it is crossed by the left main bronchus
Diaphragmatic constriction: Where it passes through the esophageal hiatus of the diaphragm
Irregular circumferential line also known as the gastric rosette
Z line
What is the Z line?
At the GE junction, the transition from esophageal to gastric mucosa is seen
Substernal burning sensation
Heartburn (pyrosis)
Difficulty swallowing
Dysphagia
Painful swallowing
Odynophagia
List some diagnostic studies used to evaluate the esophagus
Esophagogastroduodenoscopy (EGD)
Barium swallow
Esophageal pH monitoring
Esophageal Manometry
This study allows for direct visualization and capable of biopsy, variceal banding, dilation, or stent placement
Esophagogastroduodenoscopy (EGD)
This study differentiates between mechanical and motility disorders
Able to visualize reflux of barium
Barium Swallow
This study records esophageal pH and correlates acid reflux to
patient’s symptoms
Esophageal pH Monitoring
This study is used to assess esophageal motility and function
Esophageal Manometry
