Gastrointestinal Tract

• Gastroesophageal Reflux Disease (GERD)


  Backflow of highly acidic gastric contents through the Lower Esophageal Sphincter, causes inflammation, sores from acidic content
• Pathogenesis of GERD


  1. Lower esophageal sphincter is relaxed, allowing the backflow

  2. Prolonged persistence may result in esophagitis

  3. Progression can lead to ulceration, fibrotic scoring, strictures, Barrett's esophagus (remodeling of columnar tissue risk for esophageal cancer)
• Causes of GERD


  • Any condition or agent that alters closure strength of Lower esophageal sphincter
  • Increase in abdominal pressure, pregnancy (baby putting pressure in abdominal area)
  • Diet: fatty foods, caffeine, large amounts of alcohol
  • Smoking
  • Congenital abnormality such as hiatal hernia
• Hiatal Hernia


  Defect in the diaphragm that allows a portion of the stomach to pass through the diaphragmatic opening into the thorax
• Types of Hiatal Hernia

  • Sliding (common)
  • Paraesophageal
• Gastritis


  Inflammation of the stomach lining (gastric mucosa)
• Peptic Ulcer Disease (PUD)


  Ulcerations that are caused by acid and pepsin, located in either the esophagus, stomach, or duodenum
• Appendicitis


  Inflammation of the vermiform appendix
• Infectious Enterocolitis


  Infections of the GI tract that can cause diarrhea
• Pseudomembranous Enterocolitis


  Acute inflammation and necrosis, a severe form of C. Diff infection
• Peritonitis


  Inflammation of the peritoneal lining of the abdominal cavity
• Volvulus


  Sudden, tight twisting of bowel itself causing intestinal obstruction, blood vessel compression (ischemia/gangrene, necrosis, and perforation)
• Irritable Bowel Syndrome (IBS)


  Chronic (2-3 months) functional disorder with no identifiable pathology, alternating diarrhea and constipation/abdominal cramping
• Inflammatory Bowel Disease (IBD)


  Includes Crohn's disease and Ulcerative colitis, chronic inflammatory conditions of the bowel
• Crohn's disease


  Chronic inflammatory condition of the bowel that can occur anywhere along the GI tract, related to immune factors but not autoimmune
• Crohn's disease


  • Affects proximal portion of the colon or terminal ileum
  • Inflammation of all layers of intestinal wall from blockage/inflammation of lymphatic vessels
  • Suggestive findings are ulcerations, strictures, and fistulas
  • Inflammation of tissues results in pain, bleeding
  • Affected portions become thick by fibrous scar tissue with fissures, fistulas, and abscesses (cobblestone appearance)
  • Poor malabsorption leading to malnutrition
• Ulcerative colitis


  Chronic inflammatory disease of the mucosa of the rectum and colon, with exacerbations and remissions
• Ulcerative colitis


  • Ulcerated lesions from small erosions in the mucosal layer (no skip lesions)
  • Bowel wall thickens and the ulcers turn fibrotic
  • Inflammation all along the colon
  • Bloody diarrhea mixed with mucous, pain and cramping
  • More bloody stools than Crohn's
• Diverticulosis


  Outpouching of the walls of the colon
• Diverticulosis


  • Results from low intake of dietary fiber
  • Common in people over the age of 60
  • If the pouches become inflamed, can cause symptoms of diverticulitis
• Colon polyps


  Any protrusion into the GI lumen, major precursor lesion in development of colon cancer
• Colon polyps


  • Many polyps don't cause symptoms
  • Occur after age 50
  • Familial pattern
• Intestinal obstruction


  Partial or complete blockage of the small (most common site) or large bowel
• Intestinal obstruction


  • Inability of the intestinal contents to progress through the bowel
  • Fluid, gas, water, and electrolytes accumulate in the bowel
  • Can be mechanical (physical obstruction) or functional (hindered peristalsis)
• Lactase deficiency


  Inability to digest lactose due to lactase deficiency
• Celiac disease


  Malabsorption due to autoimmune response in genetically susceptible people to gluten
• Short bowel syndrome


  Malabsorption related to loss of length of bowel, usually from surgical removal
• Dumping syndrome


  Rapid emptying of stomach contents into small intestine, usually following gastric surgery
• Warning signs of GI tract cancer include black, tarry, bloody, or pencil-shaped stool, and a change in bowel habits
• Hiatal hernia


  Defect in the diaphragm that allows a portion of the stomach to pass into the thorax, causing symptoms such as heartburn and chest pain.
• Hiatal hernia symptoms


  Can include heartburn or acid reflux, chest pain, difficulty swallowing, belching or bloating, and nausea or vomiting. However, not all people with a hiatal hernia will experience symptoms.
• Symptoms of gastritis may include abdominal discomfort, indigestion, nausea, vomiting, and loss of appetite.
• Ulcers are most common in the first part of the duodenum but can occur anywhere along the gastrointestinal tract.
• Gastric ulcers typically form on the inside surface of the stomach, while duodenal ulcers develop on the inner wall of the upper part of the small intestine.
• The two main types of peptic ulcers are gastric (stomach) ulcers and duodenal (small intestine) ulcers.
• Peptic ulcer disease is characterized by chronic inflammation of the mucosa lining the digestive system, leading to the formation of painful sores called peptic ulcers.
• The most common cause of peptic ulcer disease is infection with Helicobacter pylori bacteria.
• Other causes of peptic ulcer disease include long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs), smoking, alcohol consumption, stress, and certain medical conditions like Zollinger-Ellison syndrome.
• Symptoms of peptic ulcer disease may vary depending on the location of the ulcer, but they often include abdominal pain, bloating or discomfort, nausea, vomiting, loss of appetite, weight loss, and indigestion.
• Diverticulitis: Manifestations 

  • Fever 
  • Acute lower abdominal pain (LLQ)
  • Leukocytosis