Chapter 42: Disorders of Upper and Lower GI Systems

1,

GI Tract

Mouth to Anus

Four cardinal signs and symptoms for GI disorders

• Pain

• Altered ingestion

• Altered motility

• Bleeding

Disorders of the Esophagus

• Digestive pathway 

  • Food and liquids enter the mouth 

    • Mastication(Mechanical) and addition of salivary enzymes (chemical)

  • Voluntary transport of food and liquids

    • Positioned at back of throat for esophageal entry

    • Pushed into the esophagus

  • Involuntary transit to the stomach

• Common manifestations of esophageal disorders

  • Pain, alteration in ingestion, and/or bleeding 

Dysphagia

• Difficulty of swallowing

• Causes

  • Neurological deficit

  • Muscular disorder

  • Mechanical obstruction

• Results/presentation

  • Pain with swallowing

  • Inability to swallow larger pieces of solid material

  • Difficult swallowing liquids

Causes of Dysphagia

• Congenital Atresia- walls of esophagus, food can’t get to stomach

• Congenital tracheoesophageal fistula- connection between esophagus and trachea; food gets in lungs 

• Neurologic damage to cranial nerves V, VII, IX, X, and XII

• Achalasia- Walls of the esophagus don’t contract properly; food gets stuck

Esophageal Web and Rings

• Thin membranes or folds that narrow the esophagus

• Causes: Gastroesophageal reflux, iron deficiency anemia, and autoimmune diseases

• Treatment: Dietary restrictions (soft food), Endoscopic dilation therapy 

Esophageal Cancer

• Primarily squamous cell carcinoma (most common distal esophagus)

• Significant dysphagia in later stages

• Poor prognosis due to late manifestation

• Associated with chronic irritation due to: Chronic esophagitis, Achalasia, Hiatal hernia, Alcohol abuse and smoking

Hiatal Hernia

• A hernia is a condition where an organ or tissue protrudes through a weak spot in the muscle or connective tissue that surrounds it

• HH: part of the stomach protrudes into the thoracic cavity

Hiatal Hernia- Etiology and pathogenesis

• Etiology

  • Multifactorial

  • May involve genetic link

• Pathogenesis

  • Herniation of stomach through esophageal hiatus of the diagram 

  • Lower esophageal sphincter (LES) permits reflux of gastric contents

Hiatal Hernia- Manifestations and Signs

• Classified by size: I - small, IV - large 

• Manifestations

  • May be asymptomatic

  • Frequently involves symptoms of gastroesophageal reflux

  • Type IV paraesophageal hernia may produce dyspnea, reduced exercise tolerance, syncope, may cause chronic esophagitis- inflammation on walls of esophagus

• Signs

  • Heartburn or pyrosis, frequent belching, increase discomfort when laying down, substernal pain that may radiate to the shoulder and jaw

Hiatal Hernia- treatment

• Medications for symptomatic gastric reflux

• Surgery may be indicated

Esophagitis

• Etiology 

  • Eosinophilic esophagitis(EoE)- Cause unknown; many associated factors

  • Radiation esophagitis- treatment of thoracic cancers; exacerbated by chemotherapeutic agents

  • Corrosive esophagitis- Ingestion of strong alkaline or acid substances

  • Pill esophagitis- swallowed pill lodges transversely in esophageal lumen and causes inflammation 

• Pathogenesis

  • Irritation to and inflammation of esophageal tissues lead to esophageal damage

• Manifestations 

  • vary based on etiology

• Treatment

  • vary based on etiology 

  • Thorough history and physical exam is required

Esophageal Diverticula- Etiology and Pathogenesis

• Etiology 

  • Acquired condition

  • Most common cause: impaired esophageal motility

  • May be caused by traction on esophagus due to inflammatory disease of mediastinum (e.g., tuberculosis)

• Pathogenesis

  • Pressure increases- esophageal lumen

  • Esophageal mucosa protrudes through weakened esophageal wall and produces outpouching 

Esophageal Diverticula- Manifestations and Treatment 

• Manifestations

  • Most often asymptomatic

  • Manifestations vary based on location of diverticula

  • May produce dysphagia and heartburn

• Treatment

  • Depends on size and location; surgical intervention may be needed for large diverticula

Disorders of the Stomach

• Main categories of stomach disorders

  • Disorders of secretion

  • Disorders of motility

• Associated cardinal GI symptoms

  • Pain, Altered ingestion, Altered digestion, Gastrointestinal tract bleeding

Peptic Ulcer Disease- Etiology and Pathogenesis

• Etiology

  • Various causes 

  • Most common: H. pylori infection and NSAID use

  • Contributing factors include smoking, excessive alcohol use, drug use, emotional stress, and psychosocial components 

• Pathogenesis

  • Increased gastric acid secretion or a weakened mucosal barrier leads to mucosal erosion and psychosocial components 

Peptic Ulcer Disease- Manifestations and Treatment

• Manifestations

  • Common manifestations- Epigastric pain and dyspepsia(upset stomach)

  • Common complications- Bleeding, perforation, obstruction 

• Treatment

  • Identify causative factor

  • H. Pylori- triple or quadruple therapy 

  • NSAID-induced: H2 receptor antagonist and cease NSAID

Acute Gastritis

• Etiology 

  • Infection-induced: H. pylori

  • Drug-induced: NSAIDs, steroids, some chemotherapeutic drugs, alcohol, and iron supplements

  • Ulcerohemorrhagic: physiologic stress and ischemic changes caused by shock, hypotension

• Pathogenesis

  • Acute imbalance between mucosal injury and erosive changes with histologic presence of inflammation 

• Treatment

  • Elimination of causative agent or exacerbating factors

  • Eradication of H. pylori infection if indicated

  • Medications to treat dyspepsia

  • Surgical intervention for GI bleeding 

Chronic Gastritis

• Etiology

  • Infection-induced: H. pylori

  • Chemical and caustic agents including NSAIDs, excessive alcohol ingestion, radiation exposure

  • Autoimmune disease: Crohn disease, Wegener granulomatosis, and sarcoidosis

• Pathogenesis

  • Begins with superficial gastritis

  • Progresses to atrophic atrophy

  • Gastric glandular structures are lost and/or metaplasia

  • Gastric atrophy is precursor to gastric cancer 

• Treatment 

  • Elimination of causative agent or exacerbating factors

  • Eradication of H. pylori infection if indicated

  • Medications to enhance protection of gastric mucosa

  • Acupuncture

  • Surgical intervention for GI bleeding 

Acute and Chronic Gastritis Manifestations

• Most often asymptomatic or report mild dyspepsia

• Potential symptoms may include abdominal pain or upset,  burning sensation in chest or upper abdomen, feeling of fullness, bloating, belching, and reflux

• More severe symptoms include nausea, vomiting, GI bleeding, fever, and weight loss

Gastric Outlet Obstruction- Etiology and Pathogenesis

• Etiology 

  • Includes gastric, duodenal, and/or extraluminal pathology 

  • Malignancies of digestive organs

  • Surgical and interventional-induced obstruction 

  • Metastatic cancer

• Pathogenesis

  • Mechanical obstruction in the pyloric region 

  • Food can’t move from stomach to duodenum

Gastric Outlet Obstruction- Manifestation and Treatment

• Manifestations

  • Abdominal pain, distention or bloating

  • Vomiting, dehydration, and weight loss

  • May include early satiety and nausea

• Treatment 

  • Benign cases- Nasogastric tube suction, meds to suppress gastric acid production, IV fluid and electrolyte replacement, nutritional supplementation, trial liquid diet, endoscopic ballon dilation or surgery 

  • Malignant cases- Based on underlying cause; may include stenting, chemotherapy, endoscopic ballon dilation or surgery 

  • Advanced cancers- Palliative procedures may be preferred

Stomach Cancer- Etiology and Pathogenesis

• Etiology

  • Risk factors include H. pylori infection, cigarette smoking, high alcohol ingestion, excessive dietary salt, inadequate fruit and vegetable consumption, and pernicious anemia

  • High-nitrate diet may also increase risk

• Pathogenesis

  • Tumors or neoplasms in the stomach arise from gastric mucosa (adenocarcinoma- most common 85%)

Stomach Cancer- Manifestations and Treatment

• Manifestations

  • Clinical manifestations are known as alarm features

  • Most common: Weight loss and abdominal pain

  • May include dysphagia, nausea, early satiety, occult GI bleeding and palpable abdominal mass

• Treatment

  • Treatment depends on cancer staging

  • Upper endoscopy may be used for palliative procedures 

  • May require endoscopic resection, radiation, chemotherapy, and/or surgical resection

Inflammatory bowel disease (IBD)

• Chronic inflammatory disorder involving the GIT

• 2 major IBD disorders

  • Ulcerative colitis (UC)

  • Crohn disease (CD)

Inflammatory Bowel Disease- Manifestations and Treatment

• Manifestations

  • Active: Fever, loss of appetite, weight loss, fatigue and night sweats

  • Remission: Symptoms may decrease and even disappear

• Treatment

  • Optimize quality of life by treating acute processes

  • Induce and maintain remission

  • Decrease use of corticosteroids

  • Wholesome nutrition and healthy lifestyles habits

  • Anti-inflammatory agents, Immunosuppressants, Anti-tumor necrosis factor agents, Antibiotics, Probiotics

  • Surgery if indicated 

Ulcerative colitis 

• Chronic inflammatory condition 

• Limited to mucosal layers of colon 

• Characterized by relapsing and remitting episodes of inflammation

• Develops as a continuous lesion 

Ulcerative colitis- Etiology, Pathogenesis, Manifestations 

• Etiology 

  • Not completely understood

  • Appears to involve environmental factors, microbial imbalance in the gut, genetic susceptibility, and inappropriate immune response

• Pathogenesis

  • Inflammation of mucosal and submucosal layers of colon

  • Continuous lesion inflammation may extend into the proximal colon or may affect the whole colon (pancolitis)

  • Bowel changes include epithelial damage, inflammation, crypt abscesses, and loss of goblet cells

• Manifestations

  • Bloody and/or mucoid, diarrhea, dehydration, and anemia

  • Crampy abdominal pain, pain with defecation and tenesmus

  • Involvement of the rectum may also lead to constipation 

Crohn disease

• Chronic inflammatory condition

• May involve any portion of the Gastrointestinal Tract

• Characterized by transmural inflammation of the bowel 

• Most commonly affects ileum and proximal colon 

• Lesions are not always continuous (skip lesions)

Crohn Disease- Etiology, Pathogenesis, Manifestations

• Etiology

  • Not completely understood

  • Appears to involve environmental factors, microbial imbalance in the gut, genetic susceptibility, and inappropriate immune response 

• Pathogenesis

  • Inflammation and destruction of the bowel

• Manifestations

  • Nausea, vomiting, and diarrhea with or without blood

  • Abdominal pain and pain with defecation due to anorectal fissures

  • Complications include bowel strictures, obstructions, perforations in the bowel and intra-abdominal abscesses

Appendicitis- Etiology and Pathogenesis

• Etiology

  • Not fully understood

  • Believed to be due to appendiceal obstruction 

• Pathogenesis

  • Obstruction is thought to lead to bacterial overgrowth and luminal distention

  • Increased intraluminal pressure and/or excessive inflammation can inhibit blood flow causing vascular compromise to the affected tissue

  • Appendix may become gangrenous and can rupture 

Appendicitis- Manifestations and Treatment

• Manifestations

  • Cramping abdominal pain, tenderness with palpation of the RLQ, nausea or vomiting, increased WBC count, low-grade fever

  • Treatment

    • Gold standard- Laparoscopic surgery 

Bowel Obstruction- Etiology and Pathogenesis

• Etiology

  • Most often due to adhesions (75%)

  • Other causes Hernia, Adhesions Neoplasm/tumor, Gallston ileus, Intussusception, Volvulus

• Pathogenesis

  • Intestinal tract blockage develops due to various etiologies

  • Up to 80% are small bowel obstructions (SBOs)

  • Obstruction may be partial or complete 

  • Complications include strangulation and bowel necrosis; may lead to bowel perforation, sepsis, and death

Bowel Obstruction- Manifestations and Treatment 

• Manifestations 

  • Abdominal pain, nausea, vomiting, abdominal distention, and inability to satisfactorily pass gas or stool

  • Hyperactive, high-pitched bowel sounds often present 

  • Bowel sounds will be absent if ileus develops

• Treatment

  • Medical management includes gastric decompression, intravenous fluids, and serial physical and serum tests

  • Surgery may be indicated if medical management fails

  • If strangulation and bowel ischemia present- emergent surgery needed

Diverticula

• Small outpouching (herniations) of colonic mucosa

• Protrude through muscle layers of the colon wall

• small, bulging pouches that form in the wall of the colon, a condition called diverticulosis

Diverticulosis

Diverticula without evidence of inflammation

Diverticulitis

Enflamed diverticula

Diverticular disease

• Etiology

  • Associated factors include alterations in colonic wall resistance, alterations in colonic motility, low-fiver diets, NSAID use, advanced age, obesity, and lack of exercise

• Manifestations

  • Sudden, constant abdominal pain in LLQ

  • Abdominal distention and nausea

  • Diarrhea, constipation and decreased appetite

  • Fever, tachycardia and hypotension

• Treatments

  • Outpatient management: Clear liquid diet, oral broad spectrum, antibiotics, and follow up care

  • Inpatient treatment required if suspected peritonitis or complications present

  • Inpatient treatment: Administration of intravenous fluids and antibiotics, no food or drink by mouth

  • Surgery may be indicated; depends on size 

Hemorrhoids

A swollen vein or group of veins in the region of the anus

Hemorrhoidal Disease- Etiology and Pathogenesis

• Etiology

  • Straining during bowel movement

  • Risk factors- conditions that increase intraabdominal pressure and/or impede venous return (e.g., pregnancy or portal hypertension)

• Pathogenesis 

  • Abnormal enlargement of the 3 vascular mucosal cushions (hemorrhoidal cushions) that assist with anal continence; can’t control pooping 

Hemorrhoidal Disease- Manifestations and Treatment

• Manifestations 

  • Hematochezia, itching, perianal discomfort and soiling 

  • Large hemorrhoid may produce sensation of incomplete evacuation

• Treatment 

  • Stage I and II: Diet modification, topical glucocorticoids, vasoconstrictors, analgesics, and sclerotherapy 

  • Stage III and IV: Procedural interventions (e.g., hemorrhoidal banding and surgical hemorrhoidectomy)

Colorectal Masses

• Adenomas (polyps) of the colon 

  • Precursors to most most colorectal cancers (CRCs)

  • Benign tumors 

  • Form in glandular structures in intestinal mucosal epithelium

• Colon cancer 

  • Malignant growth or tumor 

  • Results from division of abnormal cells in the colon 

  • Occurs in ascending, transverse, or descending colon

• Rectal Cancer

  • Malignant growth or tumor

  • Located up to 15cm from the anal opening 

Colorectal Cancer (CRC)- Pathogenesis

• Genetic abnormalities plus environmental factors 

• Conventional adenomas and sessile serrated polyps

  • Commonly developmental pathways

  • Chromosomal instability pathy

  • Microsatellite instability pathway

Coloretal Cancer (CRC)- Risk factors and protective factors

• Modifiable risk factors

  • Obesity, Sedentary lifestyle, Smoking, Moderate to heavy alcohol ingestion, Heavy consumption of red and processed meats, Low consumption of fruits and vegetables 

• Hereditary and medical risk factors

  • Family history of CRC and/or polyps, Inflammatory bowel disease (UC or CD), Type 2 diabetes, Aging 

• Protective Factors

  • Diet rich in whole-grain fiber, Use of NSAIDs (Ex: aspirin)

Colorectal Cancer(CRC)- Manifestations

• Typically asymptomatic

• Numerous potential manifestations

  • Hematochezia and symptoms of anemia 

  • Change in bowel habits 

  • Weight loss and fatigue

  • Generalized or localized abdominal pain 

Advanced Colorectal Cancer (CRC)- potential manifestatiosn

• Physical assessment 

  • Distended abdomen

  • Palpable abdominal mass and lymph nodes

  • Rectal cancer- palpable mass on digital exam

• Right-sided cancers (ascending colon)

  • Usually silent 

  • May become painful

  • May develop palpable mass in RLQ

  • Tumors stay to one side of the colon wall

  • Tumors stay to one side of the colon wall

  • Unlikely to develop intestinal obstruction 

  • Dark red blood in stool

• Left-sided tumors (descending colon)

  • Tumors grow circumferentially around the colon

  • Stools may become long and pencil-like

  • Can lead to intestinal obstruction

  • Bright red blood in stool 

Colorectal Cancer (CRC)- Diagnosis

• Screening for CRC

  • Early detection is essential 

  • Screening methods

    • Lower GI endoscopy, fecal tests for occult blood and DNA testing for mutant genes 

  • Screening recommendations

    • Begin screening at age 50 

  • Individuals with predisposing genetic factors

    • Begin screening earlier than age 50

Colorectal Cancer (CRC)- Staging

• Used to determine treatment

• Usually includes TNM classification

  • Tumor, lymph nodes, and metastases 

• Endoscopy may be used for staging 

• Stage I- extension to middle layer

• Stage II- extension to nearby tissue 

• Stage III- extension beyond wall

• Stage IV- beyond colon wall to lymph and other organs 

Colorectal Cancer (CRC)- Treatment 

• Depends on nature and metastasis of CRC 

• Surgery 

  • Most often used to treat CRC that has not spread

  • Adenomas may be removed during endoscopy

• If cancer extends beyond the bowel wall

  • Additional interventions may be indicated

    • Chemotherapy with or without radiation

    • Organ- or tissue-specific therapy