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Diverticular Disease and Common Anorectal Disorders

Chapter 339 | Part 10: Disorders of the Gastrointestinal System · Part 10 – Gastrointestinal Disorders · Chapter 339

Key Clinical Points

  1. Diverticulosis affects 50% of the US population >60 years; only ~5% develop acute diverticular disease.
  2. Uncomplicated diverticulitis (75%) presents with fever, leukocytosis, LLQ pain, and obstipation; CT criteria include wall thickness >4 mm and pericolic inflammation.
  3. Complicated diverticulitis (25%) includes abscess (16%), perforation (10%), stricture (5%), and fistula (2%).
  4. Hinchey Classification grades severity of complications: Ia (pericolic phlegmon), Ib (pericolic abscess), II (distant abscess), III (noncommunicating perforation), and IV (free peritonitis).
  5. Fecal incontinence (~15% prevalence) may be caused by neurologic, muscular, or miscellaneous conditions; biofeedback is the initial recommendation.
  6. Sacral nerve stimulation (SNS) for fecal incontinence requires ≥ 2 episodes/week and shows a 50% reduction in episodes.
  7. Surgical resection for diverticular bleeding is indicated if angiography/endoscopy fails, patient is unstable, or large-volume transfusion is required.
  8. Rectal prolapse is 6x more common in women >60; mucosal prolapse shows radial grooves, while full-thickness shows circumferential folds.
  9. Hemorrhoidal disease is staged (I-III) to determine treatment: Stage I involves enlargement with bleeding; Stage III requires manual reduction.
  10. Antibiotics for uncomplicated diverticulitis are reserved for high-risk patients (ASA III/IV, >5 days fever, elevated CRP/WBC) or complicated cases.

1. DIVERTICULAR DISEASE

Diverticular disease encompasses diverticulosis (presence of diverticula) and diverticular disease (symptomatic or complicated). Diverticula are outpouchings of the colonic wall.

1.1 Anatomy and Pathophysiology

• Types of Diverticulitis: ◦ True diverticulum: A saclike herniation of the entire bowel wall. ◦ Pseudodiverticulum (False): Protrusion of only mucosa and submucosa through the muscularis propria; most common in the colon. • Anatomical Location: ◦ Primarily found in the sigmoid colon due to high-pressure zones. ◦ Rectum is always spared. ◦ In Asian populations, 70% of diverticula are seen in the right colon and cecum. • Pathophysiology: ◦ Occur where nutrient arteries (vasa recta) penetrate the muscularis propria. ◦ Mechanism: High-amplitude contractions + constipated, high-fat content stool → expansion of weak areas. ◦ Consequences: Vasa recta may be compressed or eroded, leading to perforation or bleeding. • Pathogenesis Factors: ◦ Gut microbiota dysbiosis. ◦ Chronic low-grade inflammation → neuronal degeneration → dysmotility. ◦ Abnormal collagen cross-linking → loss of intestinal compliance. • Genetics: ◦ LAMB4 and TNFSF15 variants associated with early-onset, severe disease.

1.2 Epidemiology and Risk Factors

• Prevalence: ◦ 50% of US population >60 years have diverticulosis. ◦ ~5% of those with diverticulosis develop acute disease. ◦ 10-25% experience recurrent symptoms; up to 10% require surgery. • Impact: ◦ Fifth most costly GI disorder in the US; leading indication for elective colon resection. • Risk Factors: ◦ Lifestyle: Smoking, sedentary lifestyle, obesity (increased risk for complicated disease). ◦ Medications: NSAIDs, aspirin, steroids, opioids. ◦ Clinical Note: Advice to avoid nuts is based on anecdotal data.

1.3 Clinical Features and Presentation

• Uncomplicated Diverticular Disease (75%): ◦ Symptoms: Abdominal pain, fever, leukocytosis, anorexia/obstipation. • Complicated Diverticular Disease (25%): ◦ Abscess (16%), Perforation (10%), Stricture (5%), Fistula (2%). ◦ Signs of peritonitis or localized peritonitis may be present. • Special Presentations: ◦ Symptomatic colitis-associated diverticulosis (SCAD): <1% of patients; inflammation between diverticula on endoscopy; mimics IBS. ◦ Symptomatic uncomplicated diverticular disease (SUDD): Ongoing pain without evidence of overt inflammation on imaging. • Fistula Presentation: ◦ Common locations: cutaneous, vaginal, or vesicle. ◦ Symptoms: Passage of stool through skin/vagina or pneumaturia. ◦ Colovaginal fistulas are more common in women post-hysterectomy. • Table 339-1: Presentation of Diverticular Disease ◦ Uncomplicated (75%): Abdominal pain, Fever, Leukocytosis, Anorexia/obstipation. ◦ Complicated (25%): Abscess (16%), Perforation (10%), Stricture (5%), Fistula (2%).

1.4 Diagnosis and Evaluation

  1. Clinical Presentation: Fever, anorexia, LLQ pain, and obstipation.
  2. Imaging (Gold Standard): Contrast-enhanced abdominal/pelvic CT.
  3. Criteria: Sigmoid diverticula, wall thickness >4 mm, pericolic inflammation without collection of contrast or fluid.
  4. Bleeding Localization:
  5. Options: Colonoscopy, multiplanar CT angiogram, or nuclear medicine tagged red cell scan.
  6. Management of Active Bleeding (if stable):
  7. Angiography → success rate 80% for coil occlusion.
  8. Follow-up:
  9. Colonoscopy recommended ~6 weeks after first episode of uncomplicated disease or after development of complicated disease.
  10. Cancer risk: <2% overall; 6-8% in patients with complicated diverticulitis.

1.5 Medical Management

  1. Asymptomatic/SUDD Management:
  2. Lifestyle changes.
  3. Fiber: ≥ 30g daily to decrease colonic transit time.
  4. Probiotics: Lactobacillus acidophilus and Bifidobacterium strains.
  5. Rifaximin: Associated with 30% less frequent recurrent symptoms compared to fiber alone.
  6. Acute Uncomplicated Diverticular Disease:
  7. Antibiotics: Not required for routine use in immunocompetent patients; no difference in resolution time or complication risk.
  8. High-Risk Patients (Antibiotics Required):
  9. Criteria: Immunocompromised, extensive inflammation on imaging, high risk for progression, or CT findings of complicated disease.
  10. Risk Factors for Progression: ASA III/IV, >5 days of fever, elevated CRP or WBC count.
  11. Antibiotic Regimens (5-day course):
  12. Option A: 3rd-generation cephalosporin + metronidazole.
  13. Option B: Single-agent 3rd-generation penicillin (e.g., IV piperacillin or oral penicillin/clavulanic acid).
  14. Setting: Safe home treatment on oral antibiotics after 6-h observation in ED is reasonable for low-risk patients.
  15. Management of Diverticular Bleeding:
  16. Risk Factors: Hypertension, atherosclerosis, anticoagulants, NSAIDs, obesity, diabetes.
  17. Clinical Course: Most are self-limited; 25% risk of rebleeding.
  18. Surgery Indications: Refractory to angiogram/endoscopy, unstable, or large-volume transfusion required.
  19. Surgical Management (Complicated Disease):
  20. Based on Hinchey Classification:
  21. Ia (pericolic phlegmon): Laparoscopic or open colon resection; Percutaneous drainage followed by resection.
  22. Ib (pericolic abscess) & II (distant abscess): Percutaneous drainage → followed by resection with anastomosis (+/- proximal diversion).
  23. III (noncommunicating perforation): Laparoscopic washout/drainage OR resection with proximal diversion OR Hartmann's procedure.
  24. IV (free peritonitis): Hartmann's procedure OR Washout with proximal diversion.
  25. Table 339-4: Outcomes of Surgical Therapy (Hinchey):
  26. Ia: Laparoscopic/open resection → 3% leak rate, 15% morbidity.
  27. Ib & II: Percutaneous drainage + resection → 3% leak rate, 15% morbidity.
  28. III: Washout or Hartmann's → 3% leak rate, 50% morbidity/15% mortality.
  29. IV: Hartmann's or Washout → No leak data, 50% morbidity/15% mortality.
  30. General Surgical Notes:
  31. Medical therapy can be continued beyond two attacks without increased risk of perforation in uncomplicated cases.
  32. Patients with high risk (ASA III/IV, >5 days fever, high CRP/WBC) have 5x higher risk of perforation during recurrence.

Table 339-2: The Use of Fiber in Management

• Lancet (1977): Wheat/bran bread → significant reduction in symptoms. • BMJ (1981): Bran, ispaghula, placebo → no difference. • J Gastroenterol (1977): Methylcellulose → significant reduction. • BMJ (2011): Vegetarian vs nonvegetarian → 31% lower risk of DD in vegetarians. • Gastroenterology (2012): Fiber consumption → associated with great risk of DD. • JAMA (2008): Nut, corn, popcorn → higher intake = lower risk of recurrence. • Ann R Coll Surg Engl (1985): Higher fiber → 19% reduction in symptom recurrence.

2. RECTAL PROLAPSE (PROCIDENTIA)

• Epidemiology: ◦ 6x more common in women; peaks in women >60. ◦ Associated with: Urinary incontinence, rectocele, cystocele, enterocele. • Pathophysiology: ◦ Full-thickness: Circumferential protrusion of the entire wall. ◦ Mucosal: Protrusion of mucosa/submucosa only; characterized by radial grooves. ◦ Mechanism: Damage to pudendal nerves → weakened pelvic floor muscles. • Clinical Features: ◦ Symptoms: Palpable anal mass, bleeding, leakage of blood/mucus, poor hygiene. ◦ Associated conditions: Constipation (30-67%), anismus (30%), colonic inertia (10%), solitary rectal ulcer syndrome (12%). • Management: ◦ Medical: Stool-bulking agents or fiber supplementation. ◦ Surgery (Mainstay): ◦ Transperineal: Transanal proctectomy, mucosal proctectomy, or Tirsch wire. ◦ Transabdominal: Presacral suture or mesh rectopexy (Ripstein) with/without resection of redundant sigmoid.

3. FECAL INCONTINENCE

• Epidemiology: Prevalence ~15%. • Etiology (Table 339-5): ◦ Neurologic: Dementia, Brain tumor, Stroke, Multiple sclerosis, Tabes dorsalis, Cauda equina lesions. ◦ Skeletal Muscle: Myasthenia gravis, Myopathies, muscular dystrophy. ◦ Miscellaneous: Hypothyroidism, IBS, Diabetes, Severe diarrhea, Scleroderma. • Management: ◦ Initial: Biofeedback. ◦ Surgical: Sphincteroplasty (50% failure rate over 5 years) or Sacral Nerve Stimulation (SNS). ◦ SNS Criteria: FDA-approved for ≥ 2 episodes/week → 50% reduction in episodes.

4. HEMORRHOIDAL DISEASE

• Presentation: ◦ Diagnosis made on physical exam and anoscopy. ◦ Thrombosed hemorrhoids: Can be excised within 48 hours. • Management (Table 339-6): ◦ Stage I (Enlargement with bleeding): Fiber, Cortisone suppository, Sclerotherapy, Infrared coagulation. ◦ Stage III (Protrusion requiring manual reduction): Fiber, Cortisone, Rubber band ligation, Operative hemorrhoidectomy.

KEY PEARLS & HIGH-YIELD POINTS

• Diverticulitis Rule: Antibiotics in uncomplicated cases do not change outcome; reserved for high-risk (ASA III/IV, >5 days fever, high CRP/WBC) or complicated cases. • Surgical Timing: For uncomplicated diverticular disease, medical therapy can be continued beyond two attacks without increased risk of perforation. • Rectal Prolapse Distinction: Mucosal prolapse = radial grooves; Full-thickness = circumferential folds. • Fistula Complexity: Surgical approach depends on whether the tract is intersphincteric, trans-sphincteric, suprasphincteric, or extrasphincteric.

Reference Tables

TABLE 339-1 Presentation of Diverticular Disease Uncomplicated Diverticular Disease—75% Abdominal pain Fever…

Harrison's 22e, p.2579

  • Uncomplicated Diverticular Disease—75%
  • Abdominal pain
  • Fever
  • Leukocytosis
  • Anorexia/obstipation
  • Complicated Diverticular Disease—25%
  • Abscess 16%
  • Perforation 10%
  • Stricture 5%
  • Fistula 2%

TABLE 339-2 The Use of Fiber in the Management of Diverticular Disease (DD)

Harrison's 22e, p.2580

JOURNAL, STUDY YEAR PATIENTS (N) INTERVENTION STUDY LENGTH FINDINGS
Lancet, 1977 18 Wheat or bran crisp bread 3 months Significant reduction of symptoms score
58 Bran, ispaghula, placebo 16 weeks
J Gastroenterol, 1977 30 Methylcellulose 3 months Significant reduction in symptoms
47,033 Vegetarian vs nonvegetarian 11.6 years
Gastroenterology, 2012 2104 Fiber consumption 12 years Fiber associated with great risk of DD
47,288 Nut, corn, popcorn consumption 18 years
Ann R Coll Surg Engl, 1985 56 Fiber consumption 66 months Higher fiber associated with 19% reduction in symptom
recurrence

TABLE 339-3 American Society of Anesthesiologists Physical Status Classification System P1 P2 P3 P4 P5 P6

Harrison's 22e, p.2581

P1 A normal healthy patient
P3 A patient with severe systemic disease
P5 A moribund patient who is not expected to survive without the operation

TABLE 339-4 Outcome Following Surgical Therapy for Complicated Diverticular Disease Based on Modified Hinchey Staging

Harrison's 22e, p.2581

HINCHEY STAGE OPERATIVE PROCEDURE ANASTOMOTIC LEAK RATE, % OVERALL MORBIDITY RATE, %
Ia (pericolic phlegmon) Laparoscopic or open colon resection 3 15
Percutaneous drainage followed by laparoscopic or open
colon resection		 3
II Percutaneous drainage followed by laparoscopic or open colon
resection +/− proximal diversion with an ostomy		 3 15
Laparoscopic washout and drainage
or
Laparoscopic or open resection with proximal diversion (ostomy)
or
Hartmann’s procedure		 3
IV Hartmann’s procedure
or
Washout with proximal diversion		 — Overall morbidity 50%
Overall mortality 15%

TABLE 339-5 Medical Conditions That Contribute to Symptoms of Fecal Incontinence Neurologic Disorders • Dementia •…

Harrison's 22e, p.2583

  • Neurologic Disorders
  • • Dementia
    • Brain tumor
    • Stroke
    • Multiple sclerosis
    • Tabes dorsalis
    • Cauda equina lesions
  • Skeletal Muscle Disorders
  • • Myasthenia gravis
    • Myopathies, muscular dystrophy
  • Miscellaneous
  • • Hypothyroidism
    • Irritable bowel syndrome
    • Diabetes
    • Severe diarrhea
    • Scleroderma

TABLE 339-6 The Staging and Treatment of Hemorrhoids STAGE I

Harrison's 22e, p.2584

STAGE DESCRIPTION OF
CLASSIFICATION		 TREATMENT
I Enlargement with
bleeding		 Fiber supplementation
Short course of cortisone suppository
Sclerotherapy
Infrared coagulation
Protrusion with
spontaneous reduction
III Protrusion requiring
manual reduction		 Fiber supplementation
Short course of cortisone suppository
Rubber band ligation
Operative hemorrhoidectomy
Irreducible protrusion