MEDSURG | Lower GI Primer

🔥 Med-Surg Crash Review: Lower GI Problems

1️⃣ Acute Infectious Diarrhea

Main cause: Infectious agents (bacteria/viruses/parasites), often from contaminated food/water 🌎🍲. Big danger: Severe dehydration + electrolyte loss → hypovolemia & metabolic acidosis. C. diff = HIGH priority (hospital-acquired, spore-forming).

Nursing Must-Knows

• Assess: I&O, electrolytes, H&H, skin turgor, VS, stool frequency.
• Intervene: IV fluids (NS/LR), oral electrolytes (Pedialyte).
• Infection control: Soap + water only, contact precautions, bleach cleaning.
• Avoid antidiarrheals ❌ (except certain traveler’s diarrhea). Red Flags: Sunken eyes, hypotension, tachycardia.

2️⃣ Acute Abdominal Pain & Peritonitis

Often caused by inflammation, perforation, obstruction, or bleeding. Peritonitis = life-threatening!

Priority Signs 🚨

• Shock: Low BP, tachycardia, cool skin, ↓ urine.
• Peritonitis: Board-like rigidity, rebound tenderness, fever.

Nursing Actions

• ABCs + high-flow O₂
• Two large-bore IVs + rapid fluids
• NPO
• Pain control after MD eval
• Prepare for imaging or surgery

Quick Cue: Don’t apply heat to the abdomen (may worsen inflammation).

3️⃣ Inflammatory Bowel Disease (UC & Crohn’s)

Chronic, autoimmune, inflammatory flares.

UC vs Crohn’s 🔍

• UC: Continuous colon inflammation → bleeding risk + toxic megacolon
• Crohn’s: “Skip lesions,” transmural → fistulas, strictures, malabsorption

Medications

• 5-ASAs: reduce inflammation (best for UC)
• Steroids: for flares only
• Immunomodulators/Biologics: maintain remission; test for TB/Hep B/C first

Nursing Focus

• Monitor stool, H&H, electrolytes
• NPO + IV fluids during severe flares
• Skin care for diarrhea
• Diet: high-calorie, high-protein, low-residue
• B12 deficiency common in Crohn’s

Emergency: Toxic megacolon → fever, tachycardia, abdominal distention.

4️⃣ Bowel Obstruction (SBO & LBO)

Contents can’t pass → fluid backs up → massive fluid loss → hypovolemic shock ⚡

Mechanical vs Paralytic Ileus

• Mechanical: adhesions, tumors, hernias
• Non-mechanical: post-op, inflammation, meds (opioids)

Priority Signs

• Strangulation: sudden severe pain, fever, rigidity
• SBO: rapid vomiting (bile/projectile) → metabolic alkalosis
• LBO: distention, constipation → metabolic acidosis