ESOPHAGEAL DISORDERS

Gastroesophageal Reflux Disease (GERD)

Symptoms: Chronic heartburn, acid reflux, odynophagia Diagnosis: Clinical; EGD if alarm features (dysphagia, weight loss, hematemesis) Treatment: Lifestyle (elevate head, avoid triggers), PPI (first line)

Esophagitis

Types:

  • Erosive: GERD, severe reflux
  • Infectious: Candida, HSV, CMV (immunocompromised)
  • Eosinophilic (EoE): Immune response to food antigens; dysphagia, food impaction
  • Pill-induced: Tetracyclines, bisphosphonates, NSAIDs, K+ supplements
    • Mechanism: Direct caustic injury to mucosa
    • Prevention: Take upright with full glass of water, wait 30 min before lying down

Barrett’s Esophagus

Definition: Columnar metaplasia of squamous epithelium (result of chronic GERD) Appearance: “Tongue of salmon-colored mucosa at the GEJ” Risk Factors: Chronic GERD, obesity, male, White Diagnosis: EGD with biopsy Surveillance: EGD per dysplasia grade; monitor for malignant transformation

Esophageal Cancer

Types:

  • Adenocarcinoma: Classically lower 1/3; arises from Barrett’s
  • Squamous Cell: Classically upper 2/3; RF—tobacco, EtOH, achalasia

Symptoms: Progressive dysphagia (solids → liquids if severe), weight loss, melena Diagnosis: EGD with biopsy; staging = CT chest/abdomen/pelvis + PET + EUS Treatment: Localized → esophagectomy; Advanced → chemo/radiation

Dysphagia Classification

Oropharyngeal (difficulty initiating swallow):

  • Localized to oropharynx
  • Causes: CNS (stroke), H&N cancer, external compression (osteophytes), radiation
  • Evaluation: bedside swallow assessment, modified barium swallow, ENT referral

Esophageal (difficulty during swallow):

  • Episodic (liquids + solids) → MOTILITY PROBLEM
    • Esophageal spasm, achalasia, ineffective peristalsis
    • Obtain manometry (functional assessment)
  • Constant, progressive (solids then liquids if severe) → STRUCTURAL PROBLEM
    • Schatzki’s ring, stricture, cancer
    • Obtain EGD FIRST (structural assessment before manometry)

Esophageal Motility Disorders

Achalasia:

  • Pathophysiology: Incomplete LES relaxation + loss of peristalsis; autoimmune destruction of myenteric plexus
  • Symptoms: Progressive dysphagia to solids/liquids, regurgitation of undigested food, odynophagia
  • Diagnosis: Manometry (gold standard); “bird beak” on esophagram classic
  • Treatment: Pneumatic dilation (EGD), surgical/endoscopic myotomy (POEM), botox (temporary)

Distal Esophageal Spasm:

  • Pathophysiology: High-amplitude tertiary contractions → ineffective peristalsis
  • Symptoms: Dysphagia + chest pain (can mimic angina)
  • Diagnosis: Manometry (gold standard); “corkscrew esophagus” or “rosary bead” on esophagram
  • Treatment: Calcium channel blockers, nitrates, PPI

Zenker Diverticulum

Definition: Outpouching of mucosa/submucosa through Killian’s triangle (weakness between cricopharyngeus and inferior pharyngeal constrictor) Symptoms: Dysphagia, regurgitation of undigested food, halitosis, weight loss Diagnosis: Barium esophagram, transnasal endoscopy by ENT Treatment: Surgical or endoscopic closure (ENT)

Esophageal Varices

Pathophysiology: Portal HTN → dilated veins at gastroesophageal junction Prophylaxis: NSBB or endoscopic variceal ligation (EVL) Active hemorrhage: IV octreotide + band ligation Refractory bleeding: TIPS (transjugular intrahepatic portosystemic shunt) Surveillance EGDs: Per variceal grade

Mallory-Weiss Tear

Definition: Superficial tear in esophageal mucosa (not full thickness like Boerhaave) Cause: Forceful/repeated vomiting; associated with alcohol, bulimia Presentation: Hematemesis after retching/vomiting episodes Treatment: Usually self-limited; severe → endoscopic hemostasis

Boerhaave Syndrome

Definition: Full-thickness esophageal rupture Classic presentation: Severe chest pain + vomiting + subcutaneous emphysema (crepitus on chest wall) Diagnosis: CT with contrast (confirm perforation); Gastrografin swallow Treatment: Emergent surgical intervention Prognosis: High mortality if delayed >24h


GASTRIC DISORDERS

H. pylori & Peptic Ulcer Disease

H. pylori Epidemiology:

  • Colonizes ~50% of world’s population
  • Causes PUD, gastric cancer (adenocarcinoma, MALT lymphoma)

H. pylori Diagnosis:

  • Off PPIs 2+ weeks, H2-blockers 24h: Stool antigen or UBT (urea breath test)
  • On PPIs: EGD with biopsies
  • Eradication confirmation: Stool antigen or breath testing (4 weeks off abx, 2 weeks off PPI)

H. pylori Treatment:

  • Quadruple therapy (FIRST LINE): PPI + bismuth + metronidazole + tetracycline
  • Vonoprazan dual therapy (ALSO first line): Vonoprazan + amoxicillin

Peptic Ulcer Disease:

Etiologies: H. pylori (most common), NSAIDs (second), ZES (rare)

Symptoms:

  • Gastric ulcer: Gnawing epigastric pain immediately after eating
  • Duodenal ulcer: Pain 2-3 hours after meals or at night (wakes from sleep)

Complications: UGIB, perforation, peptic stricture (DU only)

Diagnosis: EGD, H. pylori testing; check fasting gastrin if recurrent/unexplained

Treatment:

  • If UGIB: Volume resuscitation (fluids, RBCs; goal Hgb >7, or >8 if CAD)
  • IV PPI then oral PPI BID × 8 weeks
  • Eradicate H. pylori if present
  • Avoid NSAIDs (or use COX-2 inhibitor + PPI if necessary)
  • IV octreotide/BB if portal hypertension

Pyloric Stenosis

Definition: Pyloric muscle hypertrophy causing gastric outlet obstruction Age: <6 months at diagnosis; peak 3-5 weeks Classic presentation: Non-bilious projectile vomiting after feeds (hypochloremic hypokalemic metabolic alkalosis) Physical exam: Palpable “olive-shaped” mass in RUQ Diagnosis: Ultrasound (gold standard) Treatment: Surgical pyloromyotomy

Gastroparesis

Etiology: DM (autonomic neuropathy), idiopathic, meds (GLP-1 RA, opioids), post-surgical Symptoms: Early satiety, nausea, vomiting of undigested food Diagnosis: EGD first to exclude obstruction; gastric emptying scintigraphy (gold standard) Treatment: Anti-emetics, prokinetics (metoclopramide max 12 weeks), dietary modification (small frequent meals, low fat/fiber), pyloromyotomy if refractory

Gastric Cancer

Epidemiology: >90% adenocarcinoma; MC in men, Hispanic, Asian/Pacific Islander, Black populations Risk Factors: Untreated H. pylori (always confirm eradication!), EBV, Lynch, FAP, tobacco, sedentary, poor diet Symptoms: Asymptomatic early; later → dyspepsia, UGIB, weight loss Red flag: New onset dyspepsia in person >60 → EGD Exam finding: Virchow node (left supraclavicular lymphadenopathy) Other types: MALT lymphoma, GIST, NET

Upper GI Bleed (UGIB)

Differential Diagnosis:

  • Chronic heartburn/reflux + odynophagia → Esophagitis
  • Epigastric pain + NSAID use → PUD
  • Cirrhosis + hemodynamic instability → Esophageal varices
  • Repeated nausea/vomiting + EtOH/bulimia → Mallory-Weiss tear
  • Severe chest pain + crepitus → Boerhaave syndrome

Evaluation & Treatment:

  1. Resuscitate: IV access, fluids, PRBCs; goal Hgb >7 (>8 if CAD)
  2. IV PPI (high-dose, BID if varices)
  3. Octreotide/NSBB if portal hypertension
  4. Labs: H. pylori stool antigen, CBC, PT/INR, lactate
  5. Diagnostic EGD (therapeutic intervention)
  6. CT Angiography if too unstable for EGD (diagnostic, NOT therapeutic; guides IR embolization)

INTESTINAL DISORDERS

Celiac Disease

Pathophysiology: Immune response to gliadin (gluten protein) Genetics: HLA-DQ2 or DQ8 required Risk Factors: FHx, T1DM, Down syndrome, Turner syndrome

Clinical Presentation:

  • GI: Diarrhea, steatorrhea, bloating, nausea; sometimes asymptomatic
  • Extraintestinal: IDA, osteoporosis, elevated ALT/AST, infertility
  • Pathognomonic: Dermatitis herpetiformis (pruritic rash on elbows, knees, buttocks)

Diagnosis:

  1. Screening serology ON GLUTEN-CONTAINING DIET: Anti-tTG IgA + total IgA (check total IgA to avoid false negatives)
  2. Gold standard: EGD with duodenal biopsies (on gluten diet)

Treatment: Strict gluten-free diet

Irritable Bowel Syndrome (IBS)

Definition: Functional GI disorder; no structural abnormality Diagnosis: Rome IV criteria (abdominal pain ≥1 day/week × 3 months + bowel habit changes) Subtypes: IBS-D (diarrhea), IBS-C (constipation), IBS-M (mixed), IBS-U (unclassified) Treatment: Dietary modifications, stress management, medications PRN (antispasmodics, loperamide, laxatives)

Inflammatory Bowel Disease (IBD)

Crohn’s Disease:

  • Location: Transmural inflammation anywhere in GI tract (MC: ileum + colon, but can be anywhere)
  • Complications: Strictures, fistulae, abscess
  • Colonoscopy findings: Cobblestone appearance, skip lesions (non-continuous)
  • Imaging: CT/MRE shows transmural inflammation

Ulcerative Colitis:

  • Location: Continuous inflammation in ascending pattern FROM RECTUM (always involves rectum)
  • Extent: Rectum only to entire colon
  • Complications: Toxic megacolon (if severe)
  • Colonoscopy findings: Confluent erythema, edema, loss of vascularity, erosions/ulcerations
  • No skip lesions

General IBD: Risk Factors: FHx, personal hx of autoimmune disease Symptoms: Abdominal pain, diarrhea, ±hematochezia Labs: ESR, CRP, fecal calprotectin; colonoscopy with biopsies

Treatment - Induction of Remission:

  • Mild: 5-ASA (mesalamine)
  • Moderate-Severe: Corticosteroids (prednisone PO, budesonide PO, methylprednisolone IV) OR biologics
  • Goal: Symptomatic AND endoscopic remission

Treatment - Maintenance:

  • Mild: 5-ASA
  • Moderate-Severe: Biologics (“-mab” drugs: infliximab, adalimumab, etc.)

Surgery:

  • Crohn’s: Stricturing disease, fistulizing disease, failure to medical therapy (NOT curative)
  • UC: Failure to medical therapy; colectomy generally curative

Toxic Megacolon

Definition: Severe complication of colonic inflammation (dilated colon with systemic toxicity) Causes: IBD (especially UC), C. difficile

Pathophysiology: Severe inflammation → colonic dilation (>6cm) → systemic toxicity

Symptoms: Fever, tachycardia, hypotension, abdominal pain/distension, altered mental status

Diagnosis: Clinical + imaging (colonic dilation >6cm WITHOUT mechanical obstruction)

  • 3-6-9 rule: Colonic dilation >6cm is classic
  • Imaging: Abdominal X-ray or CT

Treatment:

  • Medical (first line, 48-72h trial): IVF, high-dose corticosteroids, vancomycin PO + enema if C. difficile
  • Surgical (if no improvement in 48-72h or perforation): Subtotal colectomy with ileostomy

Ileus

Definition: Functional (not mechanical) impairment of GI tract; usually post-operative Symptoms: Abdominal distension, pain, decreased bowel sounds, N/V, absence of flatus/BM Diagnosis: Clinical; imaging shows dilated bowel WITHOUT transition zone (no mechanical obstruction) Imaging findings: Dilated loops, air in rectum/colon, NO transition point Treatment: Bowel rest, NG decompression if necessary

Intestinal Obstruction

Small Bowel Obstruction:

  • Etiology: Adhesions (most common post-op), hernias, volvulus, strictures, malignancy
  • Imaging: CT abdomen/pelvis (first line; shows dilated small bowel with transition point)
  • Treatment: NPO, NG tube decompression; surgery if mechanical cause confirmed

Large Bowel Obstruction:

  • MC cause: Colorectal carcinoma
  • Other: Sigmoid volvulus (MC volvulus), cecal volvulus, strictures
  • Imaging: CT abdomen/pelvis
  • Volvulus: Sigmoid (MC) > cecal; can be managed with colonoscopic decompression if uncomplicated

Ischemic Bowel Disease

Acute Mesenteric Ischemia:

  • Etiology: Arterial thrombosis/embolism (AF), venous thrombosis
  • Symptom: Severe abdominal pain OUT OF PROPORTION to exam findings
  • Labs: May have elevated lactate (late finding)
  • Diagnosis: CT angiography (gold standard)
  • Treatment: Anticoagulation; interventional embolectomy, stenting, or bypass; resect nonviable bowel

Chronic Mesenteric Ischemia (Intestinal Angina):

  • Etiology: Atherosclerotic disease
  • Symptom: Postprandial (post-eating) abdominal pain within 1 hour of eating; leads to weight loss (“food fear”)
  • Diagnosis: CT angiography
  • Treatment: Stenting, surgery if refractory

Ischemic Colitis:

  • Pathophysiology: Usually non-occlusive; affects watershed areas (SMA/IMA junction at splenic flexure, IMA/internal iliac junction at rectosigmoid)
  • Risk Factors: Atherosclerosis, HTN, DM, cocaine use, marathon running, aortic surgery
  • Symptoms: Sudden crampy abdominal pain → hematochezia within 24 hours
  • Diagnosis: CT with contrast (submucosal edema, wall thickening), colonoscopy
  • Treatment: Supportive care (fluids, antibiotics if severe); surgery if fulminant/perforation

BILIARY DISORDERS

Cholelithiasis (Gallstones)

Risk Factors: 4 F’s—Female, Forty, Fat, Fertile (also: Native American, rapid weight loss, ileal disease) Diagnosis: RUQ ultrasound (gold standard) Treatment: Asymptomatic → observation; symptomatic → cholecystectomy

Acute Cholecystitis

Definition: Inflammation of gallbladder, usually from stone impaction in cystic duct Symptoms: RUQ pain, fever, N/V (Murphy sign positive) Diagnosis: RUQ ultrasound; HIDA scan if ultrasound equivocal Treatment: Cholecystectomy (laparoscopic preferred); antibiotics if complicated

Chronic Cholecystitis

Definition: Repeated episodes of inflammation from recurrent stone impaction Diagnosis: Thickened gallbladder wall on ultrasound Treatment: Elective cholecystectomy to prevent acute episodes

Cholangitis

Definition: Infection/inflammation of common bile duct; usually from obstruction (stone, stricture, malignancy) Classic triad: Fever + RUQ pain + jaundice (Charcot triad); adds hypotension + altered mental status = Reynolds pentad Diagnosis: ERCP (diagnostic + therapeutic) Treatment: IV antibiotics, ERCP with sphincterotomy ± stone extraction


HEPATIC DISORDERS

Acute Hepatitis

Alcoholic Hepatitis:

  • Transaminitis pattern: AST:ALT >2:1 (very characteristic)
  • Diagnosis: Clinical, biopsy if needed
  • Treatment: Abstinence, corticosteroids if severe (discriminant score >32), nutritional support

MASLD (Metabolic Dysfunction-Associated Steatotic Liver Disease):

  • Definition: Hepatic steatosis + cardiometabolic risk factors (obesity, HTN, HLD, T2DM)
  • Diagnosis: FIB-4 score, transient elastography, fibroscan
  • Treatment: Avoid alcohol, weight loss >10%, GLP-1 RA, resmetirom (GLP-1/GCG agonist), vitamin E (non-diabetic MASH only)

Viral Hepatitis:

  • Hep A & E: Fecal-oral transmission
  • Hep B & C: Blood-borne transmission
  • Hep B serology:
    • Surface Ab ONLY = vaccinated
    • Surface Ab + Core Ab = previous infection (±immunity)
    • Surface Ag = ACTIVE INFECTION
  • Treatment: Supportive for A/E; antivirals for B/C

Drug-Induced Liver Injury (DILI):

  • Common drugs: NSAIDs, statins, acetaminophen, antibiotics
  • Pattern varies by agent
  • Management: Discontinue offending drug, supportive care

Autoimmune Hepatitis:

  • Diagnosis: Elevated transaminases + elevated immunoglobulins + positive autoantibodies
  • Treatment: Corticosteroids, azathioprine

Cirrhosis

Compensated Cirrhosis:

  • No complications (no ascites, encephalopathy, variceal bleed, jaundice)
  • Supportive care, address underlying cause

Decompensated Cirrhosis (must have ≥1 of):

1. Jaundice

  • Mechanism: Hepatic synthetic dysfunction
  • Management: Supportive, monitor for hepatic encephalopathy

2. Hepatic Encephalopathy:

  • Pathophysiology: Ammonia accumulation + neuroinflammation
  • Precipitants: Dehydration, infection, over-diuresis, GI bleed, high protein diet, constipation, opioids, sedatives
  • Symptoms: Forgetfulness → sleep-wake reversal → confusion/disorientation → lethargy/coma
  • Sign: Asterixis (flapping tremor)
  • Diagnosis: Clinical (ammonia levels NOT useful)
  • Treatment:
    • Lactulose (first line): Titrate to 2-3 soft BMs daily (goal 3-4/day); divides into 2-3 doses
    • Rifaximin: Add-on/second-line if inadequate lactulose response
    • Identify/treat precipitants
    • Thiamine before glucose in altered patients

3. Ascites:

  • Pathophysiology: Portal HTN → ↑ hydrostatic pressure → plasma leakage into peritoneal space
  • Diagnosis: Ultrasound; diagnostic paracentesis → calculate SAAG (serum-ascites albumin gradient)
  • Treatment:
    • Sodium restriction: <2 g/day
    • Diuretics (ratio 100:40):
      • Spironolactone 100 mg daily (potassium-sparing)
      • Furosemide 40 mg daily
    • Therapeutic paracentesis: Remove fluid; give IV albumin if >5L removed (or >4.5L per some sources)
    • Refractory ascites: TIPS

4. Spontaneous Bacterial Peritonitis (SBP):

  • Definition: Infection of peritoneal fluid (no perforation)
  • Typical organisms: E. coli, Klebsiella pneumoniae
  • Diagnosis: Paracentesis—PMN >250 cells/μL is diagnostic (don’t need positive culture)
  • Symptoms: Fever, abdominal pain, altered mental status
  • Treatment: IV cefotaxime + IV albumin (improves renal function/survival)

5. Variceal Hemorrhage:

  • Pathophysiology: Portal HTN → dilated veins at gastroesophageal junction
  • Prophylaxis: NSBB (reduces portal pressures) OR endoscopic variceal ligation (EVL)
  • Acute bleeding: Endoscopic control, blood/volume resuscitation, IV octreotide
  • Secondary prevention: NSBB + EVL
  • Refractory: TIPS

6. HCC (Hepatocellular Carcinoma) Surveillance:

  • RUQ ultrasound every 6 months in cirrhotic patients
  • Diagnosis: Imaging (CT/MRI) or biopsy if imaging equivocal
  • Treatment: Depends on stage (resection, transplant, locoregional therapy, systemic therapy)

Transaminitis Patterns (AST/ALT)

<200: Chronic liver disease, mild acute hepatitis 200-1000: Moderate acute hepatitis >1000: Acute viral hepatitis, “shock liver” (hypoxic/hypotensive), severe DILI (especially acetaminophen)


GI BLEEDING

Upper GI Bleeding

See “Upper GI Bleed (UGIB)” section under Gastric Disorders above

Lower GI Bleeding

Etiologies by age:

  • Young: Hemorrhoids, anal fissures, IBD
  • Middle-aged: Diverticular disease, angiodysplasia
  • Elderly: Diverticulosis, angiodysplasia, ischemic colitis

Workup: Colonoscopy (gold standard for diagnosis and treatment) Massive bleeding: CT angiography if unstable or ongoing transfusion requirement


COLORECTAL DISORDERS

Hemorrhoids (Internal vs External)

Internal: Painless bright red blood per rectum, may prolapse External: Painful, especially with thrombosis Treatment: Dietary fiber, stool softeners, sitz baths; procedural (banding, sclerotherapy) if refractory

Anal Fissure

Symptoms: Severe pain with bowel movements, bright red bleeding Exam: Visible tear in anal canal (posterior midline most common) Treatment: Stool softeners, sitz baths, topical nitrates/calcium channel blockers; surgery if chronic/severe

Constipation

Causes: Low fiber, dehydration, medications, hypothyroidism, IBS-C, structural obstruction Workup: Rule out obstruction; colonoscopy if age >50 or red flags Treatment: Increase fiber, fluids, physical activity; osmotic/stimulant laxatives PRN; address underlying cause

Fecal Impaction / Incontinence

Impaction: Hard stool in rectum, often from chronic constipation; manual disimpaction, softeners Incontinence: Loss of sphincter control or stool leakage; assess for fecal impaction, sphincter injury, neurologic cause

Diverticular Disease

Diverticulosis (asymptomatic):

  • Outpouching of colonic mucosa through muscular wall
  • Increased risk with age, low-fiber diet
  • No treatment if asymptomatic

Diverticulitis (symptomatic):

  • Inflammation/infection of diverticulum
  • Symptoms: LLQ pain, fever, N/V
  • Diagnosis: CT abdomen/pelvis (gold standard)
  • Treatment:
    • Uncomplicated: Outpatient antibiotics + diet (or bowel rest)
    • Complicated (abscess, fistula, perforation, obstruction): IV antibiotics ± percutaneous drainage ± surgery

Volvulus

MC types: Sigmoid (MC) > cecal Symptoms: Acute onset abdominal pain, distension, constipation Diagnosis: Abdominal X-ray (coffee bean appearance); CT confirms Treatment: Colonoscopic decompression if uncomplicated; surgery if complicated or recurrent

Toxic Megacolon

See under Inflammatory Bowel Disease section above

Rectal Prolapse

Definition: Protrusion of rectal mucosa or full-thickness rectum through anus Symptoms: Bloody stools, mucus discharge, sensation of mass Risk factors: Straining, chronic diarrhea, advanced age Treatment: Stool softeners, pelvic floor PT; surgery if refractory

Abscess / Fistula

Anorectal abscess: Collection of pus in tissue surrounding anus/rectum; presents with pain, fever, fluctuance

  • Treatment: Incision and drainage

Fistula: Abnormal tract between anal canal and skin

  • Often follows abscess drainage
  • Treatment: Surgical fistulotomy or advancement flap

Polyps

Types: Hyperplastic, adenomatous (tubular, tubulovillous, villous), sessile serrated, traditional serrated Surveillance: Based on polyp size, histology, number Management: Polypectomy; colonoscopic resection preferred


PANCREATIC DISORDERS

Acute Pancreatitis

Etiologies: Gallstones (MC), alcohol (2nd MC), hypertriglyceridemia, medications, post-ERCP, trauma, idiopathic Symptoms: Severe epigastric pain radiating to back, N/V Diagnosis: Serum/urine lipase (>3x ULN); CT shows pancreatic inflammation Labs: Elevated lipase, amylase, may have elevated transaminases (suggests biliary obstruction) Treatment: NPO, IV hydration, pain control, address underlying cause Complications: Infected pancreatic necrosis, ARDS, multiorgan failure

Chronic Pancreatitis

Etiologies: Chronic alcohol use (MC), cystic fibrosis, hereditary, autoimmune, idiopathic Symptoms: Chronic epigastric pain (may be constant or episodic), malabsorption (steatorrhea), diabetes (from endocrine dysfunction) Diagnosis: CT/MRI shows chronic changes; pancreatic elastography; 72-hr fecal fat if malabsorption suspected Treatment: Pain management, pancreatic enzyme replacement, treat diabetes, alcohol cessation


SMALL INTESTINAL DISORDERS

Appendicitis

Symptoms: RLQ pain (McBurney point—1/3 distance from ASIS to umbilicus), fever, anorexia Diagnosis: CT abdomen/pelvis Treatment: Appendectomy; antibiotics perioperatively

Celiac Disease

See under Intestinal Disorders section above

Intussusception

MC age: 6 months–3 years (ileocolic most common) Symptoms: Colicky abdominal pain, palpable RUQ mass, bloody stools (“currant jelly”) Diagnosis: Abdominal ultrasound or CT Treatment: Air or hydrostatic reduction if uncomplicated; surgery if perforation/failed reduction

Small Bowel Obstruction

See under Intestinal Obstruction section above


INGESTION OF TOXIC SUBSTANCES, FOREIGN BODIES, FOOD IMPACTION

Food Bolus Impaction

Etiologies: EoE, Schatzki’s ring, peptic stricture, esophageal cancer Symptoms: Inability to swallow, regurgitation, chest pain/pressure, drooling Red flags for perforation: Fever, subcutaneous emphysema (crepitus on chest wall), severe chest/neck pain

  • If perforation suspected → CT PRIOR to EGD Diagnosis: EGD Treatment: EGD for removal or advancement into stomach
  • Timing: Within 24 hours typically; within 2 hours if unable to tolerate secretions

Foreign Body Ingestion

MC objects in children: Coins (most common in young kids); fish/chicken bones, button batteries, magnets MC objects in adults: Food bolus, fish/chicken bones, dentures High-risk populations: Children 6 months–3 years, psychiatric patients, elderly with dentures, prisoners

Spontaneous passage: 80-90% pass spontaneously Imaging: X-ray first (radiopaque objects, location); CT if negative X-ray or perforation suspected

Location & intervention:

  • Above cricopharyngeus: ENT
  • Below cricopharyngeus: GI

Timing of intervention:

  • EMERGENT (<2 hours): Unable to tolerate secretions; high-risk objects in esophagus (button batteries, sharp objects)
  • URGENT (2-24 hours): Esophageal FB; sharp objects in stomach/duodenum; magnets within endoscopic reach
  • NON-URGENT (<72 hours): Smooth objects in stomach past endoscopic reach; objects likely to pass

Toxic Ingestion: Caustic Material

Examples: Bleach, drain cleaner, detergent, toilet cleaner Presentation: Oropharyngeal burns, drooling, dysphagia/odynophagia, chest pain, abdominal pain, stridor (suggests supraglottic injury)

Management:

  1. Assess airway: Intubate early if stridor or respiratory distress
  2. IV access, IV PPI
  3. DO NOT induce emesis (worsens injury)
  4. DO NOT give activated charcoal
  5. CXR, CT C/A/P if perforation suspected
  6. EGD within 12-24 hours (assess degree of ulceration)
  7. Prognosis: Deep ulceration → ↑ risk of stricture, esophageal SCC

Toxic Ingestion: Toxic Substances & Body Packing

Management:

  • Contact Poison Control for all suspected toxic ingestions
  • Activated charcoal: Most effective <1 hour; binds most drugs (NOT EtOH, metals, lithium, caustics)
    • C/I: Unprotected airway, bowel obstruction/perforation
  • Whole Bowel Irrigation (PEG 1-2 L/hr): For drug packets, iron, lithium, sustained-release meds not amenable to AC

Ingested drug packets:

  • Imaging: CT (gold standard)
  • Rupture risk: Life-threatening
  • Management: Whole bowel irrigation if asymptomatic; surgery if ruptured or obstruction

Toxic Ingestion: Acetaminophen Overdose

Toxicity Mechanism: Toxic metabolite NAPQI accumulates → hepatocellular necrosis

Clinical Phases:

  • Phase 1 (<24h): N/V, malaise, anorexia; labs often NORMAL (can falsely reassure)
  • Phase 2 (24-72h): RUQ pain, AST/ALT rise, elevated PT/INR
  • Phase 3 (72-96h): Peak hepatotoxicity—AST/ALT >1,000 (often 3k-10k), jaundice, coagulopathy, encephalopathy, AKI
  • Phase 4 (4 days–2 weeks): Recovery OR progression to acute liver failure/death

Evaluation:

  • Plot 4-hour serum APAP level on Rumack-Matthew nomogram
  • Start NAC if at or above “possible toxicity” line (don’t wait for full results)

Treatment:

  • IV N-acetylcysteine (NAC): Replenishes glutathione, helps metabolize toxic NAPQI
    • Nearly 100% protective if given <8 hours of ingestion
    • Still beneficial up to 24 hours
    • Continue even if acute liver failure develops (improves transplant survival)
    • Continue until AST/ALT trending down, INR <2, clinical improvement
  • Activated charcoal: If <4 hours and no C/I
  • Liver transplant: Consider referral

NUTRITION & METABOLIC DISORDERS

Food Allergies & Intolerances

IgE-Mediated (Immediate, Anaphylactic):

  • Top 9 allergens: Milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans, sesame
  • Treatment: Epinephrine 0.3 mg IM to anterolateral thigh (first-line); antihistamines/steroids are adjuncts

Food Protein-Induced Enterocolitis Syndrome (Non-IgE mediated):

  • Presentation: Severe N/V/D within 1-4 hours
  • Population: Typically infants; often outgrow by age 4
  • Common triggers: Soy, milk, grains
  • Treatment: Avoid trigger food

Lactose Intolerance:

  • Mechanism: Lactase enzyme deficiency
  • Symptoms: Bloating, gas, diarrhea after dairy
  • Treatment: Dietary restriction OR lactase enzyme supplementation
  • Pearl: Supplement calcium if avoiding dairy

Malnutrition & Refeeding Syndrome

Protein/Calorie Malnutrition:

  • Assessment: By RD using ASPEN criteria
  • Patterns:
    • Calorie deficiency: Wasting (fat, muscle), preserved albumin initially, “skin and bones”
    • Protein deficiency + adequate calories: Edema, ascites, low albumin, hepatic steatosis
  • Supplemental feeding: Enteral (PO, NG, PEG, G-J) always preferred to TPN when possible

Refeeding Syndrome:

  • Definition: Life-threatening complication when nutrition abruptly resumed in severely malnourished patient
  • Mechanism: Insulin secretion → sudden intracellular shift in phosphate, K+, Mg → electrolyte abnormalities
  • Risk factors: NPO >5-7 days, anorexia nervosa, chronic EtOH, cancer cachexia, starvation
  • Complications: Cardiac dysrhythmias, respiratory failure, seizures, rhabdomyolysis, death
  • Prevention (NICE Guidelines):
    • Start at 10 kcal/kg/day, increase slowly over 4-7 days
    • Supplement phosphate, K+, Mg BEFORE refeeding starts
    • Thiamine 200-300 mg before and during refeeding
    • Monitor electrolytes Q6H in high-risk patients
    • Give thiamine BEFORE glucose in altered patients (prevent Wernicke encephalopathy)

Hypervitaminosis & Hypovitaminosis

General principles:

  • Fat-soluble vitamins (A, D, E, K): Can accumulate → toxicity
  • Water-soluble vitamins: Excess excreted in urine (rare toxicity)

Vitamin Deficiency Sites & Patterns:

  • Duodenum: Iron absorption
  • Jejunum: ADEK, water-soluble vitamins
  • Ileum: B12, bile salts
  • Post-bariatric: ADEK, iron, B12, thiamine (especially RYGB)

Specific Deficiencies:

VitaminSymptomsAssociations
ANight blindness, xerophthalmiaFat malabsorption, RYGB
B1 (Thiamine)Beriberi (wet: CHF/edema; dry: neuropathy/ataxia/weakness); Wernicke’s (encephalopathy, LR palsy, nystagmus, ataxia); Korsakoff’s (confabulation, anterograde amnesia)Chronic EtOH, RYGB
B3 (Niacin)Pellagra (4 D’s: dermatitis, diarrhea, dementia, death)EtOH, RYGB
B6 (Folate)Megaloblastic anemia, impaired cognitionEtOH, pregnancy, phenytoin, RYGB
B12Megaloblastic anemia, paresthesias, glossitisCrohn’s ileitis, ileal resection, strict vegans, atrophic gastritis/pernicious anemia
CScurvy (fatigue, bleeding, poor wound healing, “corkscrew hairs”)EtOH, poor intake, RYGB
DRickets (children; poor growth, delayed fontanelle, frontal bossing, rachitic rosary, bowing legs), osteomalacia (adults; bone pain, fractures), hypocalcemia, 2° hyperparathyroidismLimited sunlight, CKD, fat malabsorption, obesity, RYGB, phenytoin
KProlonged PT/INR, easy bruising, newborn hemorrhagic diseaseWarfarin, fat malabsorption, RYGB

Vitamin Excess:

Vitamin A Excess:

  • Sources: Excess supplementation, tretinoin
  • At-risk: Infants, children (most susceptible); pregnant women (teratogenic)
  • Acute symptoms: N/V, dizziness, blurry vision
  • Chronic symptoms: Dry/cracked skin, hair loss, brittle nails, hepatic fibrosis/cirrhosis, idiopathic intracranial hypertension

Vitamin D Excess:

  • Source: Excess supplementation
  • Mechanism: ↑ calcium absorption → hypercalcemia
  • Symptoms: Kidney stones, muscle weakness, cardiac arrhythmias, GI symptoms (abdominal pain, N/V, constipation)

Metabolic Disorders

Phenylketonuria (PKU):

  • Epidemiology: MC European ancestry; autosomal recessive
  • Pathophysiology: Inability to metabolize phenylalanine → tyrosine (varies in severity)
  • Presentation: Progressive developmental delay if undiagnosed; “musty urine” odor
  • Diagnosis: Newborn metabolic screening
  • Treatment: Low phenylalanine diet, blood monitoring

G6PD Deficiency:

  • Epidemiology: African, Mediterranean, Asian descent; X-linked (MC in males)
  • Pathophysiology: ↓ G6PD → ↓ resilience to oxidative stress → hemolysis
  • Triggers: Fava beans, medications (sulfa, macrobid, antimalarials), infections
  • Asymptomatic until oxidative stress → acute hemolysis (jaundice, dark urine, splenomegaly, back pain, renal insufficiency)
  • Diagnosis: Newborn metabolic screening; labs show hemolytic anemia (↓Hgb, ↑LDH, ↓haptoglobin, ↑reticulocytes)
  • Treatment: Eliminate triggers, hydration, transfusions for hemolytic episodes, folic acid (support RBC production)

Paget’s Disease:

  • Epidemiology: MC males >60; unclear etiology (possibly paramyxovirus: measles/mumps)
  • Pathophysiology: Disordered bone remodeling—lytic phase → mixed phase → sclerotic phase
  • Location: 1+ bone (MC: pelvis, femur, lumbar spine, skull)
  • Presentation: Bone pain, pathologic fractures
  • Diagnosis: X-ray (lytic/sclerotic lesions, “cotton wool appearance”); biopsy (mosaic lamellar bone, large osteoclasts with many nuclei)
  • Treatment: Bisphosphonates, surgery for fractures/malformations, PT

Rickets:

  • Pathophysiology: Vitamin D deficiency → defective bone mineralization (osteomalacia in adults)
  • Causes: Intestinal malabsorption, ↓ intake, ↓ sunlight, phenytoin, chronic liver/kidney disease
  • Symptoms/Signs: Bone pain, fractures, hypocalcemic Sx (tetany, paresthesias); poor growth, delayed fontanelle closure, frontal bossing, craniotabes, rachitic rosary, enlarged epiphyses, bowing legs
  • Labs: ↓ Vitamin D, ↓ calcium, ↑ ALP, ↑ PTH
  • Treatment: Dietary supplementation (Vitamin D, calcium), address underlying cause

KEY PANCE GI EXAM PEARLS

Esophagus:

  • Barrett’s = columnar metaplasia from chronic GERD; risk for adenocarcinoma
  • Achalasia = bird beak + manometry; treat with dilation/myotomy/botox
  • Zenker diverticulum = dysphagia/regurgitation/halitosis; requires surgery
  • Always obtain EGD before manometry for constant/progressive dysphagia
  • Boerhaave = emergency; high mortality if delayed >24h

Stomach:

  • H. pylori MUST be confirmed eradicated after treatment
  • PUD: GU pain immediately after eating; DU pain 2-3h after eating or at night
  • New dyspepsia age >60 → EGD
  • Pyloric stenosis = non-bilious projectile vomiting in infants <6 months

Intestines:

  • Celiac = anti-tTG IgA + total IgA on gluten diet; gold standard = EGD biopsy
  • IBD: Crohn’s = transmural + anywhere; UC = continuous from rectum only
  • Toxic megacolon = >6cm dilation + systemic toxicity; medical 48-72h, then surgery
  • Ischemic colitis = watershed areas; sudden pain → hematochezia

Liver:

  • Ascites: sodium <2g/day + diuretics (100:40 ratio spiro:lasix) + therapeutic paracentesis
  • SBP = PMN >250 (don’t need positive culture); treat with cefotaxime + albumin
  • HE = lactulose 3-4 stools/day ± rifaximin; identify precipitants
  • Variceal bleed = octreotide + band ligation; TIPS if refractory

Toxins:

  • APAP: Plot 4-hour level; NAC within 8h (nearly 100% effective), still beneficial ≤24h
  • Caustic ingestion: DO NOT induce emesis or give AC; EGD within 12-24h
  • Foreign body: 80-90% pass spontaneously; emergency if button battery/sharp in esophagus

Nutrition:

  • Refeeding syndrome: NPO >5-7 days; thiamine BEFORE glucose; supplement electrolytes BEFORE feeding
  • RYGB: At risk for ADEK, iron, B12, thiamine deficiency
  • Enteral nutrition always preferred to TPN