GI Patho PP

• Disorders of the Esophagus

  • Dysphagia
  • Esophagitis
  • Gastroesophageal reflux disease (GERD)
  • Esophageal varices
  • Esophageal cancer
• Dysphagia

  • Difficulty swallowing
  • Associated with lack of gag reflex which occurs in degenerative neurologic diseases and stroke (50-70% of individuals affected by stroke have a decreased gag reflex)
  • Also associated with increased risk of aspiration pneumonia
  • Diverticulum (a weakening in the wall resulting in an outpouching or sac where food accumulates and creates obstruction)
• Dysphagia


  • Esophageal strictures (narrowing), rings, or tumors
  • Scarring of the throat
  • Scleroderma, hardening of connective tissue (autoimmune disease, injury, inflammation)
  • Achalasia - motility problem of smooth muscle resulting in lack of peristalsis ( muscle doesn't effectively contract)
• Esophagitis

  • Acute or chronic inflammation of esophagus
  • Most commonly caused by reflux of hydrochloric acid from the stomach
  • Can be caused by a fungal infection in immunocompromised patients (Candida albicans)
• Gastroesophageal Reflux (GERD)


  • Most common and costly GI disorder
  • Over 700,000 hospitalized in US/yr
  • Occurs in 20% of population
  • Decreased muscular tone in cardiac sphincter, also with delayed gastric emptying
• Factors related to GERD

  • Alcohol
  • Chocolate
  • Caffeine
  • Fatty meals
  • Meds (anticholinergics, beta agonists, calcium channel blockers, nitrates, progesterone)
  • Nicotine
  • Obesity
  • Pregnancy
• Upper GI Bleed

  • Bleeding in the esophagus, stomach, or duodenum
  • Melena and hematemesis
  • Risk from elevated ammonia levels
  • Cool, clammy skin, and orthostatic blood pressure changes
• Causes of Upper GI Bleed

  • Lesion
  • Ulceration
  • Erosion
  • Varicosed vein
  • Tear to GI lining
• Etiologies of Upper GI Bleed

  • Peptic Ulcer Disease (PUD)
  • Esophageal varices
  • Mallory-Weiss syndrome
  • Esophageal cancer
  • Hemorrhagic gastritis
• Esophageal Varices

  Increased resistance to venous blood flow through the liver – backing up in adjacent vessels

  - can't clot effectively

  - diluted capillaries
• Esophageal Cancer

  • 17,000 patients per year, 16,000 deaths
  • Usually seen in 60 – 70 year old
  • Genes and environment (mutation in tumor suppressor gene TP53)
  • Risks include tobacco use and GERD, HPV may also be involved
• Hiatal Hernia


  • A portion of the stomach pushes up through the diaphragm into the thoracic cavity
  • Increased intra-abdominal pressure (obesity and pregnancy are risk factors)
• Gastritis

  Inflammation of the stomach lining

  - acute or chronic
• Causes of Gastritis

  • Infection
  • Stress
  • Allergy
  • Bile reflux
  • Alcohol
  • Radiation
  • Direct trauma
  • Use of NSAIDs or corticosteroids (decrease protective prostaglandins)
• Peptic Ulcers


  • An inflammatory erosion in the stomach (gastric) or duodenum
  • Duodenum 4x as common
  • Chronic wound that doesn't heal because of infection by H. pylori
• Dumping Syndrome


  • Rapid gastric emptying
  • Common complication of surgical procedures that remove part of the stomach, such as bariatric surgery
• Hernia


  • Protrusion of a section of the small intestine through a weakened abdominal wall muscle

  -Inguinal and umbilical are some of the most common locations

  • Men > women
• Risk factors for Hernia

  • Obesity
  • Ascites
  • Pregnancy
  • Heavy lifting
  • Chronic cough
  • Chronic constipation
• Gastroenteritis


  • Irritation to lining of the GI tract by a pathogen or toxin
  • About 100 million cases per year in US
  • Dehydration and electrolyte imbalances can occur
• Microorganisms that cause Gastroenteritis


  • Norovirus
  • Rotavirus
  • Coronavirus
  • Some bacteria
  • Clostridium difficile
  • Parasites such as ameba and Giardia
• Pathophysiology of Gastroenteritis

  1. Microbes attach to GI mucosa, invade the mucosal layer or produce toxins that result in an inflammatory response involving the GI epithelium

  2. Increase in fluid in the intestinal lumen overwhelms the ability for fluid to be reabsorbed by the GI epithelium - watery diarrhea
• Celiac Disease

  • Gluten-sensitive enteropathy

  - autoimmune

  - 1% of American population

  • Gluten-derived peptide, gliadin, damages the intestinal mucosa
  • More than 90% of those affected have HLA-DQ2.5
• Pathophysiology of Celiac Disease


  • Autoimmune, inflammatory process that destroys the intestinal villi - reduction in surface area causing atrophy of the intestinal wall

  Digestion issues:

  1. Can't digest carbohydrates - buildup of gases abdominal bloating and diarrhea

  2. Can't absorb proteins - affects muscle maintenance and building

  3. Can't digest fats --> loss of fat-->soluble vitamins (A,D,E, and K) -->fat loss in stool (steatorrhea)
• Short Bowel Syndrome

  • Occurs with any pathology that leaves less than 200 cm of small intestine: traumatic injury, mesenteric ischemia, Crohn's disease, tumors, radiation
  • Average length of small intestines is 600 cm
  • Decreased absorptive surface > nutritional deficiencies including reabsorption of bile salts
• Bowel Obstruction

  • Abdominal adhesions (60%) - internal scar tissue
  • -Appendectomy, colorectal surgery, gynecological and upper GI procedures can also cause bowel obstruction
  • Malignancy
  • Crohn's disease
  • Hernias
• Peritonitis

  • Inflammation of the serous membrane that surrounds the abdominal cavity and covers the organs
  • Most common when organs rupture introduces bacteria, bile, acids, and/or enzymes into the sterile peritoneal environment
• Disorders of the Large Intestine

  • Intestinal motility and constipation
  • Inflammatory bowel disease
  • - Ulcerative colitis
  • - Crohn's disease
  • - Diverticulitis
  • Bowel obstruction
  • Appendicitis
  • Irritable bowel syndrome (IBS)
• Constipation

  • Drugs with anticholinergic activity can decrease motility
  • Narcotics
  • Insufficient water
  • 25-35% over 65 yr
• Inflammatory Bowel Disease (IBD)


  • Chronic remitting disorders that result in inflammation of the GI tract

  - Chron disease

  - Ulcerative colitis

  • In US, approximately 1.6 M affected (795k w/ Chron's Disease and 910k w/ Ulcerative colitis)
  • Prevalence is highest in Western countries; incidence is increasing in developing countries
• Risk factors for Crohn's Disease

  • Genetic predisposition
  • Ethnicity
  • Cigarette smoking
  • Family history
  • Consumption of refined sugars and saturated fats
  • Caucasians
  • Ashkenazi Jewish background
• Diverticulitis


  • Inflammation of pouches
  • Unknown causes
  • 80-85 % without symptoms
• Mechanical blockage of Bowel Obstruction

  • Adhesions
  • Tumors
  • Abdominal hernia
  • Foreign body
  • Gallstone that has migrated into the intestine
  • Bolus of undigested food
  • Fecal impaction
• Non-mechanical Bowel Obstruction

  - Disruption of peristalsis, paralytic ileus
• Appendicitis

  • Inflammation of blind-ended pouch that protrudes from the cecum (vestigial organ)
  • most common cause of "acute abdomen"
  • hypothesized that it is caused by nearly complete blockage by stool or calcified feces
  • lower in cultures that consume a high fiber diet
  • cystic fibrosis puts child at higher risk
• Irritable Bowel Syndrome (IBS)

  • Abdominal pain and altered bowel activity in the absence of specific pathology
  • cause unclear
  • can have diarrhea, constipation, or combination of the two
  • 25 % of US population has symptoms
• Lower GI Bleed

  Blood or bloody diarrhea

  - black tarry or bright red? (hematochezia)
• Viral Hepatitis: A

  • Contaminated food or water (fecal-oral route), mostly mild disease without complications
• Viral Hepatitis: B


  • blood and body fluids
  • 2 billion people worldwide have evidence of current or past infection
  • chronic HBV infection can exist w/o evidence of active disease
  • sx gradually subside, course is variable from moderate illness to fulminate hepatitis
  • Perinatal transmission
  • associated with unprotected sexual activity
• Risk factors for Hepatitis B& C


  • Unprotected sexual activity
  • Handling blood products
  • IV drug use
  • Hemodialysis
• Viral Hepatitis: C


  • blood and body fluids
  • targets hepatocytes and B lymphocytes
  • reproduces rapidly: 10 trillion particles per day
  • HCV can live dormant in pt for years before sx develop
  • chronic HCV increase risk of hepatocellular cancer