Definition & temporal classification
Acute: \le 14\,\text{days}
Persistent: >14\,\text{days} but \le 30\,\text{days}
Chronic: >30\,\text{days}
Etiology & pathophysiology
Primary U.S. cause ➜ infectious organisms (esp. viruses)
Notable pathogens & presentations
Norovirus, rotavirus – watery stool
E.\,coli\,O157! :! H7 – hemorrhagic colitis, possible HUS
Giardia lamblia – protozoan; greasy, foul-smelling stool
Clostridium\,difficile (CDI) – antibiotic-associated colitis
Mechanisms of injury
Secretory: organisms ↑ secretion/↓ absorption in enterocytes; little/no inflammation
Inflammatory: organisms destroy mucosa, provoke colonic inflammation, generate toxins ➜ impaired absorption, exudation
Transmission pathways
Contaminated food/water
Fecal–oral contact, esp. in LTCFs, day-care
Host susceptibility
Elderly (↓ immunity, comorbidities)
↓ Gastric acidity (PPIs, H2 blockers) ➜ ↑ survival of pathogens
Altered gut flora (broad-spectrum antibiotics)
Immunocompromised states; jejunal tube feedings
Non-infectious causes
Drugs: laxatives, Mg antacids, antibiotics, metformin, chemotherapy
Food intolerances: large sugar alcohol load, lactose, gluten, caffeine
Osmotic: rapid GI transit (tube feeds, gastrectomy)
Malabsorption: celiac disease, short-bowel syndrome
Clinical manifestations
Upper GI source: large-volume watery stool, crampy peri-umbilical pain, N/V, minimal fever
Lower GI source: small-volume, frequent, possibly bloody stool; fever
Severe cases: dehydration (\textit{fluid volume deficit}), hypokalemia, metabolic acidosis
CDI: fulminant colitis, toxic megacolon, perforation
Diagnostic studies
Stool culture (blood, mucus, WBCs, ova/parasites, C. diff toxin)
Blood culture if septic/immunocompromised
Labs: CBC, electrolytes, \text{BUN/Cr}, serum osmolality, pH
Specialized: fecal fat/protein, GI hormones for secretory diarrhea
Interprofessional management
Prevent transmission (contact precautions)
Replace fluids & electrolytes (oral rehydration or IV LR/NS)
Protect perianal skin (barrier creams, meticulous hygiene)
Antidiarrheals (if no infection suspected)
Coaters (bismuth), absorbents (kaolin-pectin), opiate analogs (loperamide, diphenoxylate), antisecretories (octreotide)
Contraindicated in IBD flare ➜ risk of toxic megacolon
CDIFF-specific care
HAI; spores survive \le 70\,\text{days} on surfaces
Strict contact isolation; soap-and-water handwash, 10 % bleach surface disinfection
First-line Rx: oral vancomycin 125\,\text{mg} q6h × 10 d OR fidaxomicin
Alternatives: metronidazole (mild), vanco + IV metro (severe/complicated)
Ileus ➜ vancomycin retention enema
Stop non-essential abx, laxatives, antidiarrheals
Recurrent CDI ➜ fecal microbiota transplantation (FMT) via colonoscopy, enema, or nasoenteric tube
Consider probiotic (\textit{Lactobacillus}) prophylaxis
Nursing priorities
Assume infectious until proven otherwise
Accurate I&O; daily weight; inspect skin
Teach hygiene, safe food handling, early HCP contact for blood/dehydration
Definition & features
Symptom, not a disease
Difficult/infrequent BM, excessive straining, sensation of incomplete evacuation
Acute: <1\,\text{week}; Chronic: >3\,\text{months}
Risk factors
Low-fiber diet
Decreased physical activity
Ignoring urge to defecate ➜ rectal desensitization, stool desiccation
Emotional stress, anxiety, depression
Conditions slowing transit: DM, Parkinson’s, hypothyroid, spinal cord injury, scleroderma
Meds: opioids, anticholinergics, Ca/Al antacids, iron, antidepressants
Chronic stimulant laxative use ➜ cathartic colon (dilated, atonic)
Clinical manifestations
Hard, dry, infrequent stool; straining
Abdominal distention, bloating, flatulence, rectal pressure
Hemorrhoids, anal fissures
Diverticulosis (elderly)
Obstipation/fecal impaction, perforation (rare)
Diagnostics
Thorough H&P; DRE, abdominal exam
Alarm signs >6 wk: hematochezia, anemia, wt loss, pain, FHx CRC/IBD
Imaging: plain ABD film, barium enema, colonoscopy, anorectal manometry, balloon expulsion, sitz-mark transit study
Management
↑ dietary fiber (20–30 g/day), fruits/veg/whole grains; fluid \ge 2\,\text{L}/day
Regular exercise & defecation schedule
Laxatives (bulk-forming, osmotic, stool softeners, stimulants) – use judiciously
Enemas for acute impaction
Peripherally acting \mu-opioid receptor antagonists (methylnaltrexone) for OIC
Biofeedback for pelvic-floor dysfunction
Surgery (subtotal colectomy, ostomy) for refractory cases
Nursing care
Individualize plan; educate on diet, hydration, exercise
Encourage not ignoring urge; proper positioning; privacy
Discourage chronic laxative/enema abuse
Qualities: dull, aching, diffuse, intermittent >3 mo
Common etiologies: IBS, chronic pancreatitis, chronic hepatitis, PID, adhesions, mesenteric ischemia
Work-up: comprehensive H&P, pain diary, labs, endoscopy, CT/MRI, laparoscopy
Therapy: treat cause; multidisciplinary pain management
Functional disorder: recurrent abdominal pain + altered bowel habits without structural cause ≥3 mo
Rome IV diagnostic criteria
Abdominal pain on \ge 1\,\text{day/week} × 3 mo, with ≥2:
Related to defecation
Change in stool frequency
Change in stool form
Subtypes
IBS-C (constipation-predominant)
IBS-D (diarrhea-predominant)
Mixed
Unsubtyped
Gender trends
Women 2–2.5× > men; more IBS-C, bloating, fatigue, depression
Men: more IBS-D, less likely to seek care
Triggers
Psychological stress, anxiety, depression
Post-infectious gut dysbiosis
Food sensitivities: gluten, FODMAPs (fructans, lactose, sorbitol, etc.)
Symptoms
GI: crampy pain, bloating, gas, mucus in stool, sense of incomplete evacuation
Non-GI: fatigue, HA, sleep disturbance
Management
Therapeutic alliance, reassurance
Cognitive-behavioral therapy, stress reduction
Diet: low-FODMAP, trial gluten-free, adequate fiber for IBS-C
Pharmacology
IBS-D: loperamide, bile-acid binders, eluxadoline, rifaximin, alosetron (\textbf{Drug Alert: ischemic colitis})
IBS-C: soluble fiber, osmotic laxatives, lubiprostone, linaclotide
Antispasmodics (dicyclomine), TCAs/SSRIs for pain modulation
Chronic immune-mediated inflammation with remissions & exacerbations
Two primary phenotypes
Ulcerative colitis (UC): mucosal layer of colon/rectum
Crohn’s disease (CD): transmural, any part mouth→anus; terminal ileum common
Etiology
Genetic susceptibility (>200 genes, NOD2 variants)
Environment: diet high in refined sugar, fat, ω-6; smoking, stress, NSAIDs, antibiotics, OCPs
Microbiome dysregulation
Autoimmune dysregulation ➜ uncontrolled cytokine cascade (TNF-α, IL-12/23) → tissue destruction
Pathology
Crohn’s
Skip lesions, cobblestone mucosa, strictures, fistulas, abscesses
Transmural granulomatous inflammation
UC
Continuous lesion from rectum proximally
Only mucosa/submucosa; pseudopolyps; toxic megacolon risk
Clinical presentation
CD: diarrhea, crampy pain, weight loss, low-grade fever, fatigue, occasional rectal bleeding
UC: bloody diarrhea; stool frequency correlates w/ severity
Mild <4/d; Moderate ≤10/d; Severe 10–20/d ± fever, anemia, tachycardia
Pain, weight loss, fatigue
Complications
Local: hemorrhage, strictures, perforation, abscess, fistula, CDI, toxic megacolon
Systemic: ↑ risk CRC (esp. >8 yr disease), cholangiocarcinoma, malabsorption, osteoporosis, spondyloarthropathies, PSC, erythema nodosum, uveitis
Diagnostics
CBC (anemia, leukocytosis), BMP (lytes), albumin, ESR/CRP, stool ova/parasites & cultures
Imaging: double-contrast BE, small-bowel follow-through, CT/MRI enterography, US
Endoscopy: colonoscopy w/ biopsies; capsule endoscopy for CD
Therapeutic goals
Rest bowel, control inflammation, fight infection, correct malnutrition, alleviate stress, symptom relief, QOL improvement
Pharmacologic therapy (step-up vs step-down)
5! -! ASA agents: sulfasalazine, mesalamine (PO/PR) – 1st line UC
Corticosteroids: prednisone, budesonide, IV methyl-pred for flares (short-term)
Immunomodulators: azathioprine, 6-MP, methotrexate (maintenance)
Biologics
Anti-TNF: infliximab (IV), adalimumab, certolizumab, golimumab
Integrin antagonists: natalizumab, vedolizumab
Risks: infection (TB, HBV), malignancy; no live vaccines
JAK inhibitor (tofacitinib) for moderate-severe UC
Surgical options
UC: curative
Total proctocolectomy + IPAA (J- or S-pouch)
Total proctocolectomy + permanent ileostomy
CD: surgery for complications; resection w/ anastomosis, strictureplasty; risk short-bowel syndrome
Nutrition
Individualized; high-cal/high-protein during remission
Acute flare: enteral elemental formulas; may need TPN
Supplements: folate (sulfasalazine), Ca/Vit D (steroids), B12 (ileal disease), Fe, Zn, Mg, trace elements
Food diary to identify triggers (dairy, high-fat, cold foods, high-fiber in strictures)
Nursing care
Monitor hemodynamics, pain, stool output, weight, labs
I&O, daily wt, assess for bleeding, infection, skin integrity
Pre-/post-op ostomy teaching
Coping strategies; CCFA resources
Gerontologic considerations
Second incidence peak ~60 yr; left-sided UC common
Atypical sx; polypharmacy ↑ adverse effects
↑ infection, malignancy risk; ambulatory limitations
Definitions
Diverticula: saccular mucosal outpouchings in colon wall, most sigmoid
Diverticulosis: presence of multiple diverticula without inflammation
Diverticulitis: inflammation of a diverticulum
Etiology
Weak points where vasa recta penetrate circular muscle
↑ intraluminal pressure from constipation/straining
Low-fiber diet, obesity, inactivity, smoking, excess ETOH, NSAIDs, genetics
Clinical manifestations
Diverticulosis: often asymptomatic; possible LLQ pain, bloating, flatulence, change bowel habit; hematochezia
Diverticulitis: acute LLQ pain, fever, leukocytosis, ↓/absent BS, N/V; elderly may be afebrile
Complications: perforation, abscess, fistula, peritonitis, hemorrhage
Diagnostics
CT Abd w/ oral contrast (preferred)
Sigmoidoscopy/colonoscopy once inflammation resolved
Labs: CBC, UA, blood cultures, FOBT; XR to r/o free air
Management
Prevention: high-fiber, ↓ fat/red meat, weight control, exercise
Acute mild: bowel rest (clear liquids), oral abx, analgesia
Severe/septic/comorbid: NPO, NG suction, IV fluids, broad-spectrum IV abx, monitor for abscess/peritonitis
Recurrent/complicated: elective sigmoid resection ± temporary colostomy
Education: 2 L fluids/day, avoid straining, lifting, tight belts
General: defective absorption of fat, CHO, protein, vitamins, minerals, water
Hallmarks: weight loss, diarrhea, steatorrhea (bulky, pale, foul, oil-ring stool)
Common causes
Lactose intolerance (most prevalent)
IBD, celiac disease, tropical sprue, cystic fibrosis
Short-bowel syndrome, pancreatic insufficiency, bile-acid deficiency
Diagnostic tests
Stool fat (\textit{Sudan III}), fecal elastase
D-xylose absorption, lactose tolerance/H2 breath
Serology: anti-tTG IgA for celiac
Imaging: small-bowel follow-through, CT, capsule endoscopy
Labs: CBC, PT (Vit K), vit A, carotene, lytes, Ca, cholesterol
Autoimmune enteropathy triggered by gluten (prolamines) in genetically predisposed (HLA-DQ2/DQ8)
Associated autoimmune disorders: RA, T1DM, thyroiditis
Manifestations
Classic: foul diarrhea, abdominal pain, flatulence, distention, malnutrition
Atypical: osteoporosis, fertility issues, neuropathy, dermatitis herpetiformis
Laboratory: Fe-def anemia, ↓ folate, B12
Diagnosis:
Serology (anti-tTG, EMA) while on gluten diet
Upper endoscopy + duodenal biopsy (villous atrophy)
Genetic HLA typing (supportive)
Management
Strict gluten-free diet (no wheat, barley, rye)
Dietician referral; monitor Ca/Vit D, Fe, B12
Resources: CSA, CDF
Absent/low lactase enzyme ➜ unabsorbed lactose fermented in colon
Populations: Asians, Africans, premature infants, Congenital rare
Symptoms within 30 min of dairy: bloating, cramps, flatulence, diarrhea
Diagnosis: lactose tolerance test, H2 breath test, genetic testing
Treatment: lactase enzyme (Lactaid), lactose-free diet, Ca & Vit D supplementation
<25–30 % functional small intestine
Causes: massive resections (Crohn’s, volvulus), congenital atresia, necrotizing enterocolitis
Manifestations: chronic diarrhea, malnutrition, wt loss, dehydration, steatorrhea, lyte deficits (Mg, Zn)
Care
Fluid/lyte replacement, antidiarrheals (loperamide), acid suppression
Nutritional support: TPN initial, transition to enteral; high-complex CHO, low-fat; MCT oil
GLP-2 analog (teduglutide) to enhance adaptation
Intestinal transplant for refractory failure
Rare mesenchymal tumor from interstitial cells of Cajal; KIT or PDGFRA mutation
Early nonspecific: early satiety, bloating, N/V, altered BM
Late: GI bleed, obstruction
Diagnosis: EUS-guided biopsy, CT/MRI
Treatment: surgical resection; imatinib (tyrosine-kinase inhibitor) for unresectable/metastatic
Varicose dilatation of hemorrhoidal veins
Internal (above dentate line)
External (below dentate line)
Risk factors: pregnancy, constipation/straining, diarrhea, heavy lifting, prolonged sitting/standing, obesity, ascites
Clinical
Internal: painless bright-red bleeding, mucus, prolapse causing dull ache
External: bluish mass, pruritus, burning, edema; thrombosis → severe pain
Diagnosis: inspection, DRE; anoscopy/sigmoidoscopy for internal
Management
Conservative: high-fiber diet, ↑ fluids, stool softeners, topical anesthetics/astringents, sitz baths
Office procedures: rubber-band ligation, infrared coagulation, sclerotherapy, laser
Surgical hemorrhoidectomy for large prolapse or thrombosis
Post-op nursing: pain control (opioids, NSAIDs, topical), packing care, encourage fiber/fluids, avoid straining, watch for urinary retention, bleeding
Linear ulcer in anoderm from trauma (hard stool, vaginal delivery) or IBD/STD
Severe burning pain with BM, bright-red bleeding
Therapy: fiber, fluids, stool softeners, topical nitroglycerin/diltiazem, botulinum inj; lateral internal sphincterotomy if chronic
Abnormal tract from anal canal to perianal skin/vagina; often post-abscess or Crohn’s
Purulent/bloody drainage, pruritus
Treatment: fistulotomy; complex tracts may need LIFT procedure, advancement flap, fibrin glue/plug