Lower GI system

Lower G.I. System Overview

Small Intestines

• The small intestine consists of three sections: duodenum, jejunum, ileum.
• Extends from:
  • Pylorus to ileocecal valve.
• Primary functions:
  • Digestion and absorption of nutrients across the intestinal wall into the circulation.
  • Enzymes secreted through the small intestine aid in food breakdown into absorbable nutrients.

Large Intestines

• Composed of three sections: cecum, colon, and rectum.
• Extends from:
  • Ileocecal valve to anus.
• Primary function:
  • Absorption of water.
  • Formation of feces.

Assessment of Lower G.I. System

• Methods of Assessment:
  • Inspection
  • Auscultation
  • Percussion
  • Palpation
• Inquire about bowel habits.

Diagnostic Studies of Lower G.I. (LGI)

Stool Tests

• Hemoccult Test:
  • Used to identify blood in stool.
• Stool Culture and Sensitivity:
  • Detects pathogens in stool samples and assesses susceptibility to antibiotics to help diagnose gastrointestinal infections.

Lower G.I. Diagnostics

• Small Bowel Follow Through:
  • Ingestion of barium followed by x-rays to track passage through the small intestine.
• Barium Enema:
  • Visualizes the colon and rectum using barium.
• KUB (Kidneys, Ureters, Bladder):
  • Visualizes abdominal and urinary system structures.

Visual Inspections of the Bowel with Lighted Instruments

• Anoscope
• Proctoscopy
• Sigmoidoscopy (Rigid or Flexible)
• Colonoscopy
  • Associated with LGI endoscopy.

Endoscopy Care

• Prepare patient by ensuring:
  • Clear liquid diet for 24 hours prior.
  • No red dyes.
  • NPO (nothing by mouth) after midnight.
  • Bowel preparation the evening before the procedure, typically with enemas the morning of.
  • Routine postoperative care.

Capsule Endoscopy

• Patient swallows a pill that images the G.I. tract.
• Primarily diagnoses:
  • Crohn's disease
  • Celiac disease
  • Sites for GI bleeding.
• Procedure specifics:
  • NPO for 8 hours before (may allow water).
  • Liquid intake 2 hours after ingestion; food after 4 hours.
  • Images transmitted to a recorder worn for about 8 hours.
  • Pill will pass in stool; no MRI until pill is excreted.

Diarrhea

• Defined as increased frequency and liquidity of stool.
• Common Causes:
  • Infectious:
  • Viruses (e.g., norovirus, rotavirus).
  • Bacteria (e.g., C. diff, E. coli).
  • Parasites.
  • Inflammatory:
  • Conditions like Crohn's disease, ulcerative colitis.
  • Medications:
  • Antibiotics, laxatives, chemotherapy drugs.
  • Food Intolerances:
  • Lactose, gluten.
  • Surgical Complications:
  • Bowel resection, dumping syndrome.

Nursing Interventions for Diarrhea

• Recommendations include:
  • Monitor intake and output (I&O), weight, and skin integrity.
  • Encourage oral rehydration or intravenous (IV) fluids.
  • Check for signs of hypokalemia.
  • Use antidiarrheals cautiously, especially in infections like C. diff.
  • Implement contact precautions if infectious.

Medications for Diarrhea

• Loperamide (Imodium OTC):
  • Slows peristalsis and increases absorption.
• Diphenoxylate + Atropine (Lomotil):
  • Reduces motility with anticholinergic effects.
• Bismuth Subsalicylate (Pepto-Bismol):
  • Coats GI lining and protects mucous membranes.
• Kaolin-pectin:
  • Thickens stool and absorbs excess fluids.
• Dicyclomine:
  • Decreases GI motility and cramping.
• Octreotide:
  • Decreases intestinal secretion.

Clostridium difficile (C. diff)

• Description:
  • Gram-positive, spore-forming anaerobic bacterium causing colon inflammation.
• Risk Factors:
  • Antibiotic use, hospitalization, immunosuppression, older age, previous C. diff infections.
• Symptoms:
  • Profuse watery diarrhea, abdominal cramping and pain, fever, nausea, leukocytosis, pseudomembranous colitis, potential for toxic megacolon or perforation (life-threatening complications).
• Treatment:
  • Antibiotics; in severe cases, fecal transplant.
• Precautions:
  • Extended contact precautions required due to infection risk.

Escherichia coli (E. coli) O157:H7

• Source:
  • Comes from ingestion of contaminated food/beverages, especially undercooked meat (e.g., hamburger).
• Symptoms:
  • Severe diarrhea (often bloody), cramping, low-grade fever; typically lasts 5-7 days.
  • Can lead to hemolytic uremic syndrome with a mortality rate of about 5%; approximately 10% may require lifelong dialysis.
• Treatment:
  • Primarily supportive; may include fluids and electrolytes; rifaximin may be prescribed.

Constipation

• Definition:
  • Infrequent or difficult passage of stools accompanied by straining, hard stools, or a perception of incomplete evacuation.
• Causes:
  • Low fiber intake, inadequate fluid intake, lack of physical activity, ignoring the urge to defecate, certain medications (e.g., opioids, anticholinergics, calcium channel blockers, iron supplements), metabolic/endocrine disorders, neurological disorders.
• Complications:
  • Hemorrhoids, diverticulosis, impaction, perforated colon.

Types of Laxatives

Bulk Forming Laxatives

• Function: Absorb water into stool to increase bulk and promote natural peristalsis.
• Examples:
  • Psyllium (Metamucil)
  • Methylcellulose (Citrucel)
  • Polycarbophil (Fibercon)
• Instructions:
  • Not for immediate relief; mix with at least 8 oz of water or juice and follow with another glass of water.
• Side Effects:
  • Bloating, gas, fullness, risk of bowel obstruction.

Osmotic Laxatives

• Definition:
  • Contain substances (salts, sugars, PEG) that are poorly absorbed, creating an osmotic effect pulling water into the bowel.
• Results in:
  • Softer stool and increased bowel volume, triggering peristalsis.
• Examples:
  • Polyethylene glycol (MiraLAX), Lactulose, Magnesium hydroxide (Milk of Magnesia), magnesium citrate, sorbitol.
• Indications:
  • Short-term constipation relief, bowel prep for procedures.
• Side Effects:
  • Bloating, epigastric fullness, nausea/vomiting, stomach cramps, diarrhea, electrolyte imbalances with prolonged use.

Emollient Laxatives

• Definition:
  • Stool softeners increasing water and fat penetration into stool, making it easier to pass.
• Examples:
  • Docusate sodium (Colace), Docusate calcium (Surfak).
• Indications:
  • Prevent constipation, particularly in post-operative cases (especially cardiac), postpartum women, or patients with hemorrhoids.
• Side Effects:
  • Diarrhea, stomach cramps, throat irritation (for liquid forms).

Lubricant Laxatives

• Definition:
  • Coats stool and intestinal lining to retain moisture, easing passage.
• Examples:
  • Mineral oil, Fleets Enema with oil.

Stimulant Laxatives

• Definition:
  • Trigger rhythmic muscle contractions in the intestine, moving stool along.
• Examples:
  • Bisacodyl (Dulcolax), Senna (Senokot, Ex-Lax), castor oil (rarely used today).
• Usage:
  • Fast onset; for short-term use only, as dependence may occur.

Methylnaltrexone

• Brand: Relistor.
• Properties:
  • Peripherally acting mu-opioid receptor antagonist specifically for opioid-induced constipation.
• Administration: Subcutaneous injection.

Small Bowel Obstruction

• Definition:
  • A blockage of the small intestine preventing normal passage of contents.
• Causes:
  • Mechanical: Adhesions, hernias, tumors, volvulus, intussusception, foreign bodies, gallstones.
  • Non-mechanical: Paralytic ileus.
• Symptoms:
  • Cramping abdominal pain, nausea, projectile vomiting (may be bilious or fecal-smelling), abdominal distension, absent/high-pitched bowel sounds, inability to pass gas or stool.
• Treatment:
  • NPO, NG tube for low intermittent suction, IV fluids with electrolytes, monitor intake and output, analgesics and antiemetics, frequent abdominal assessments.
  • If no resolution or signs of perforation, surgery is necessary.

Large Bowel Obstruction

• Definition:
  • A blockage in the colon preventing the passage of stool and gas, often slower than small bowel obstruction but equally serious.
• Causes:
  • Mechanical: Colorectal cancer, diverticulitis with stricture, volvulus, fecal impaction, hernias.
  • Non-mechanical: Ogilvie syndrome.
• Symptoms:
  • Lower abdominal cramping/pain, abdominal distension, nausea and vomiting, high-pitched/absent bowel sounds, fecal-scented breath.
• Treatment:
  • NPO, IV fluids and electrolytes, NG tube if vomiting or decompression needed, monitoring for signs of perforation or sepsis, and possible surgery.

Bowel Perforation

• Definition:
  • A hole or tear in the intestinal wall, allowing leakage into the abdominal cavity; a surgical emergency.
• Causes:
  • Trauma, infection/inflammation, bowel obstruction, inflammatory bowel diseases (Crohn’s or ulcerative colitis), peptic ulcers, ingested foreign body, cancers, or during surgical procedures.
• Symptoms:
  • Sudden severe abdominal pain (may report temporary relief), rigid/board-like abdomen, absent bowel sounds, nausea, vomiting, signs of shock.
• Treatment:
  • NPO, IV fluids, broad-spectrum IV antibiotics, NG tube to decompress stomach, surgical repair (laparotomy).

Lower G.I. Bleed

• Definition:
  • Bleeding from the jejunum, ileum, colon, rectum, or anus.
• Common Causes:
  • Diverticulosis, colorectal cancer, inflammatory bowel disease (IBD), hemorrhoids, anal fissures, polyps, ischemic colitis.
• Symptoms:
  • Hematochezia or melena (depending on bleed location), fatigue, pallor, tachycardia, hypotension, abdominal pain/cramping.
• Diagnostics:
  • Colonoscopy, occult blood test, monitor CBC.
• Treatment:
  • Address underlying causes, provide IV fluids, blood transfusions, endoscopic interventions, and surgical options in severe instances.

Acute Abdomen

• Definition:
  • A non-specific diagnosis suggesting an abdominal condition needing immediate surgery.
• Symptoms:
  • Severe abdominal pain, guarding or rebound tenderness, rigid/board-like abdomen, nausea/vomiting, fever/chills, absent/hypoactive bowel sounds, tachycardia, hypotension, pallor, diaphoresis.

Appendicitis

• Definition:
  • Inflammation of the vermiform appendix; common cause of acute abdomen potentially leading to rupture and peritonitis.
• Symptoms:
  • Initially vague periumbilical pain that shifts to right lower quadrant (McBurney’s point), may show positive Rovsing or Psoas signs, rebound tenderness, guarding and rigid abdomen, nausea/vomiting, low-grade fever, anorexia, increased pain with movement or coughing.
• Treatment:
  • NPO, IV fluids, IV antibiotics, pain management, appendectomy (surgical removal).

Diverticulosis

• Definition:
  • Formation of small, bulging pouches (diverticula) in colon lining, most often in sigmoid colon.
• Asymptomatic typically unless progresses to diverticulitis.
• Causes:
  • Low fiber diet, constipation, decreased muscle strength, obesity, aging, predisposition from diverticulum or bowel surgeries.
• Treatment:
  • High-fiber diet, adequate hydration, regular physical activity, avoid straining during bowel movements, avoidance of seeds/nuts/popcorn (outdated practice).

Diverticulitis

• Definition:
  • Inflammation/infection of diverticula in colon; can lead to abscesses, perforation, or peritonitis.
• Symptoms:
  • Left lower quadrant pain, fever/chills, nausea/vomiting, constipation or diarrhea, bloating, rebound tenderness, elevated white blood cell count.
• Treatment:
  • Mild Cases (Outpatient): Clear liquid diet followed by gradual advancement as tolerated, oral antibiotics, rest and follow-up.
  • Severe/Complicated Cases (Inpatient): NPO, IV fluids, IV antibiotics, pain management, monitoring.
  • Surgery for recurrent episodes, presence of abscess or fistula, perforation, or obstruction.

Irritable Bowel Syndrome (IBS)

• A complex disorder with:
  • Abdominal pain and altered bowel habits without an identifiable pathophysiological cause.
• Four subtypes:
  • IBS-C: constipation dominant
  • IBS-D: diarrhea dominant
  • IBS-M: alternating between diarrhea and constipation
  • IBS unclassified: meets criteria but not categorized.
• No definitive diagnostic test; tests performed to exclude other disorders.
• Diagnostic Criteria: Rome IV Diagnostic Criteria or Manning Criteria.

IBS Diet Recommendations

• Encourage high-fiber diet; emphasize avoidance of FODMAPs:
  • Fermentable Oligosaccharides (e.g., wheat, rye, garlic, onions, legumes).
  • Disaccharides: (e.g., milk, soft cheese, yogurt, ice cream).
  • Monosaccharides: (e.g., apples, pears, watermelon, honey, high fructose corn syrup, dried fruits).
  • Polyols: (e.g., sugar-free candy, peaches, plums, cherries, cauliflower, mushrooms).
• Suitable Foods:
  • Carrots, spinach, bananas, blueberries, strawberries, oranges, kiwi, rice, oats, eggs, turkey, fish, almond milk.

IBS Medications

• 5 HT3 blockers: Alosetron (helps slow peristalsis).
• 5 HT4 agonists: Prucalopride (stimulates peristalsis).
• Chloride Channel Activators: Lubiprostone (increases gut motility via intestinal fluid secretion).
• GI Antispasmodics/Anticholinergics: Dicyclomine (blocks muscle spasms within the GI tract).

Inflammatory Bowel Disease (IBD)

• Description:
  • A chronic autoimmune inflammation of the GI tract, with two main forms:
  • Crohn’s Disease
  • Ulcerative Colitis.
• Characterized by:
  • Exacerbations and remissions.
  • Unknown exact cause.
• Symptoms include:
  • Persistent diarrhea
  • Abdominal pain
  • Cramps.
• Additional complications may involve:
  • Uveitis
  • Cholangitis
  • Nephrolithiasis
  • Cholelithiasis
  • Joint disorders
  • Skin disorders
  • Oral ulcerations.

Crohn’s Disease

• Pathophysiology:
  • Triggering factors lead to helper T-cells releasing pro-inflammatory mediators.
  • Results in excessive and uncoordinated inflammatory responses.
• Characteristics:
  • Occurs in segments termed "skip lesions."
  • Impacts all layers of the bowel wall.
• Common manifestations:
  • Thickened segments, narrowed lumen, “string sign.”
  • Symptoms include:
  • RLQ (right lower quadrant) abdominal pain not resolved by bowel movement, diarrhea, nausea/vomiting, constipation, fatigue, fever, anorexia, weight loss.
• Occurs most frequently in:
  • Ileum/colon.
• Description of lesions:
  • Deep ulcers (fissures) between raised areas of mucosa, creating a cobblestone appearance.
• Chronic inflammation can lead to:
  • Abscesses
  • Fistulas
  • Strictures
  • Adhesions.

Ulcerative Colitis (UC)

• Definition:
  • A chronic inflammatory disease affecting the colon and rectum.
• Main manifestation:
  • Bloody diarrhea.
• Inflammation pattern:
  • Starts in the rectum and moves proximally.
• Symptoms include:
  • LLQ (left lower quadrant) abdominal pain.
• Affects:
  • Only mucosa and submucosa along continuous lesion patterns.
• Risk:
  • Higher incidence of colorectal cancer.

Surgical Options for Ulcerative Colitis

• Proctocolectomy with Permanent Ileostomy:
  • Removal of colon and rectum, closing the anus.
• Kock Pouch:
  • Distal ileum used to create a pouch holding stool, requiring catheterization for emptying.
• Abdominal Colectomy with Ileoanal Anastomosis:
  • Colon is removed; ileum sutured to anal canal.
• Colectomy with Mucosal Proctectomy:
  • Two-step procedure involving ileal pouch creation and temporary ileostomy, removing colon and rectal mucosa.

Differences Between Ulcerative Colitis and Crohn’s Disease

Medications for Inflammatory Bowel Disease

• 5-Aminosalicylic Acid: (sulfasalazine, mesalamine, olsalazine) - decrease inflammation by blocking prostaglandin/leukotriene production; primary use in UC.
• Antimicrobials/Anti-infectives: (metronidazole, ciprofloxacin) - reduce bacterial overgrowth in Crohn’s; treat secondary infections.
• Corticosteroids: (dexamethasone, budesonide, prednisone, solu-medrol) - decrease inflammation.
• Biological Therapies: (infliximab, adalimumab, natalizumab) - alter immune response.
• Immunosuppressants: (azathioprine, mercaptopurine, cyclosporine) - modify immune system activity to reduce inflammation.
• Antidiarrheals: - symptomatic relief and bowel rest.

Rectal/Anal Fistulas

• Definition:
  • Abnormal tunnels form between rectum or anal canal and skin near the anus.
• Results from:
  • Infection, abscess, inflammatory conditions.
• Symptoms:
  • Persistent drainage of pus or stool near anus, pain, redness/swelling around anus, perianal abscesses.
• Treatment:
  • Antibiotics, wound packing for healing from inner to outer, monitor for infection or worsening drainage, sitz baths for comfort and hygiene, provide emotional support (pain/embarrassment), and educate on hygiene, stool softeners, follow-up care.

Colostomies

• Definition:
  • An opening from the colon to the abdominal wall.
• Stool consistency depends on:
  • Ascending colostomy: liquid stool
  • Transverse colostomy: mushy/semi-formed stool
  • Descending/sigmoid colostomy: formed stool.
• Can be temporary or permanent.
• Indications include:
  • Colon cancer, diverticulitis, bowel obstruction, trauma.

Ileostomy

• Definition:
  • An opening from the ileum to the abdominal wall.
• Output:
  • Liquid to semi-liquid with digestive enzymes (more irritating to skin).
• Typically permanent but can be temporary; indications include ulcerative colitis, Crohn’s disease, familial polyposis, trauma.

Types of Ostomies

End Colostomy

• The bowel is severed, and the proximal portion is brought through the abdominal wall.
• Can be ileostomy or colostomy; may be temporary or permanent.

Loop Colostomy

• A loop of the bowel is pulled through the abdomen and opened, resulting in two openings in one stoma (one for stool, one for mucus).

Double Barrel Ostomy

• Contains two stomas: proximal (drains feces) and distal (secretes mucus, known as mucous fistula); often temporary post-trauma.

Preoperative Care

• Educate patient, provide emotional support, perform bowel prep if indicated, administer IV fluids or TPN as needed, complete pre-op checklist (vitals, labs, consent), ensure NPO status after midnight.

Postoperative Care

• Monitor for:
  • NG tube presence post-procedure
  • IV fluids for hydration/electrolytes
  • Pain management techniques
  • Early ambulation
  • S/S of complications
  • Stoma site appearance (should be pink to red, moist, slightly protruding).

Complications of Ostomies

• Common complications associated with major abdominal surgery include:
  • Hemorrhage
  • Shock
  • Pulmonary embolism
  • Peritonitis/sepsis
  • Paralytic ileus
  • Intestinal obstruction
  • Anastomotic leak
  • Stoma necrosis
  • Malabsorption
• Specific for ileostomies: urinary calculi, gallstones, ileitis.

Ostomy Care Recommendations

• Empty ostomy bag when 1/3 full.
• Regular changing every 3 days or as necessary.
• Remove bag/barrier carefully; wash, dry, inspect stoma; measure stoma; cut stoma barrier accordingly; apply paste and barriers securely; ensure bag is clamped properly.
• Instruct patient on odor control techniques.

Nutrition for Patients with Ostomies

• Low residue diet for 6-8 weeks.
• Small, frequent meals advocated.
• Encourage thorough chewing.
• Gradual introduction of new foods, one at a time.
• Ensure adequate fluid intake—at least 2 liters/day (3 liters for ileostomy).
• For ileostomies, avoid high-fiber or hard-to-digest foods (e.g., corn, poppy seeds, popcorn).

Factors Causing Flatus

• Factors include:
  • Swallowed air from smoking, chewing gum, or straws; certain foods (e.g., broccoli, Brussels sprouts, cabbage, cauliflower, cucumber, mushrooms).
• Prevention strategies:
  • Avoid gas-producing foods; consume crackers, toast, yogurt.

Ostomy Irrigation Process

• Ostomy irrigation involves introducing warm water through a colostomy to create a regular bowel schedule.
• Indicated for patients with descending/sigmoid end colostomies.
• Procedure instructions: position at least 18 inches above the stoma, evacuate quickly unless cramping occurs, use 500-1000 mL volume, employ cone tip to prevent perforation.

Colorectal Cancer

• Definition:
  • Cancer of the colon or rectum, often originating from adenomatous polyps.
• Growth:
  • Often slow-growing and asymptomatic initially.
• Risk Factors:
  • Age (>50), family history of colorectal cancer/polyps, inflammatory bowel disease (especially ulcerative colitis), high-fat low-fiber diet, smoking, alcohol use, sedentary lifestyle, obesity, type 2 diabetes.
• Symptoms:
  • Changes in bowel habits (diarrhea/constipation), rectal bleeding or blood in stool (often occult), unexplained weight loss, anemia (iron deficiency), abdominal discomfort, gas, fullness, sensation of incomplete evacuation.
• Treatment:
  • Colectomy (with or without ostomy) for colon cancer, abdominal-perineal resection for rectal cancer, chemotherapy/radiation if indicated, targeted therapy using monoclonal antibodies.
• Importance of routine colonoscopy screenings for prevention.

Hernias

• Definition:
  • Protrusion of an internal organ (usually intestine) through an abnormal opening or weakened cavity wall.
• Causes:
  • Abnormal muscle wall weakening and splitting; can occur anywhere, most commonly in the abdomen.
• Types of Hernias:
  • Inguinal (Direct and Indirect): Protrudes in the groin area; intra-abdominal fat or small intestine enters inguinal canal.
  • Femoral: Fat in femoral canal enlarges and pulls peritoneal contents into hernia sac.
  • Ventral: (Umbilical at umbilical ring)—caused by increased abdominal pressure; contains insensible fat or bowel, within limits of umbilical ring.
  • Epigastric: Occurs between umbilicus and xiphoid process.
  • Incisional: Forms from previous abdominal surgical incision.

Types of Hernias by SIR Classification

• Strangulated Hernia:
  • Blood supply is cut off; requires emergency surgical intervention.
• Incarcerated Hernia:
  • Hernia is trapped outside the peritoneal cavity.
• Reducible Hernia:
  • Hernia can be pushed back into the peritoneal cavity.

Treatment of Hernias

• Truss:
  • A firm pad held against the hernia by a belt to prevent protrusion.
• Surgeries:
  • Herniorrhaphy: Surgical repair of hernia.
  • Hernioplasty: Surgical repair using mesh reinforcement in the weakened area.

Hemorrhoids

• Definition:
  • Swollen or dilated veins in the rectal area.
• Causes include:
  • Straining, prolonged constipation, heavy lifting, prolonged sitting or standing, portal hypertension, increased intra-abdominal pressure, pregnancy, obesity, heart failure.
• Types:
  • Can be internal or external.
• Symptoms:
  • Pain, itching/burning; bleeding with defecation is common with external hemorrhoids only if a vein ruptures; constipation/diarrhea can aggravate.
• Treatment includes:
  • Conservative for symptoms/pain relief, possible rubber band ligation, sclerotherapy, cryosurgery, infrared laser procedures; severe cases may require hemorrhoidectomy.

Abdominal Trauma

• Definition:
  • Injury to the abdomen, possibly damaging internal organs.
• Types:
  • Can be blunt or penetrating.
• Symptoms:
  • Abdominal pain, distention, rebound tenderness, Cullen's sign, Grey-Turner's sign, signs of hemorrhage.
• Management includes:
  • Monitor for internal bleeding (in/out of G.I. tract), assess vital signs and perform an abdominal assessment; do not remove any foreign object (e.g., knives).
• Treatment:
  • Diagnostic to identify bleeding, IV fluids, NG tube, likely surgical intervention.

Malabsorption

• Definition:
  • Impaired absorption of nutrients from the gastrointestinal tract, leading to nutrient deficiencies.
• Causes include:
  • Celiac disease, lactose intolerance, pancreatic insufficiency, short bowel syndrome, bile salt deficiency, Crohn’s disease, infectious causes (e.g., Giardia).
• Symptoms:
  • Chronic diarrhea, steatorrhea, weight loss, bloating, fatigue, nutritional deficiencies.

Lactose Intolerance

• Definition:
  • Inability to digest lactose due to lactase enzyme deficiency in the small intestine.
• Lactase breaks down lactose into glucose and galactose.
• Undigested lactose remains in the gut, fermented by bacteria causing:
  • Gas, bloating, diarrhea.
• Types:
  • Primary: Genetic decrease in lactase.
  • Secondary: Damage to intestinal lining (e.g., from infections, celiac disease, Crohn’s).
  • Congenital: Rare; born without lactase enzyme.
• Diagnostics:
  • Lactose tolerance tests, hydrogen breath tests.
• Management:
  • Restrict lactose in foods, check ingredient labels for milk derivatives, consider lactase enzyme supplements before meals.

Celiac Disease

• Definition:
  • Chronic autoimmune disorder triggered by gluten, causing small intestine villi damage and malabsorption.
• Pathophysiology:
  • Gluten ingestion leads to immune reaction causing inflammation and villous atrophy.
• Nutrient deficiencies may occur (especially iron, calcium, folate, fat-soluble vitamins).
• Diagnostics:
  • Serologic testing for tTG-IgA (most sensitive); total serum IgA.
  • Endoscopy with bowel biopsy confirms villous atrophy. Dietary intake of gluten must be ongoing to obtain accurate biopsy results.
• Treatment:
  • Adherence to a strict gluten-free diet (avoid wheat, barley, rye).

Short Bowel Syndrome

• Definition:
  • Malabsorption disorder resulting from a significant portion of the small intestine being absent or dysfunctional.
• Results in:
  • Poor absorption of water, nutrients, and calories due to reduced surface area.
• Diagnostics:
  • Patient history, stool analysis, blood tests for electrolyte/nutrient levels, imaging to assess remaining bowel.
• Nutrition considerations:
  • Parenteral nutrition, enteral nutrition, special high-protein, low-fat diets, easy to digest foods.
• Medications:
  • Anti-diarrheals, proton pump inhibitors, bile acid binders.
• Surgical options may include bowel lengthening procedures or intestinal transplants in severe cases.