Meckel's Diverticulum

Overview

Meckel's diverticulum is the most common congenital malformation of the gastrointestinal tract, occurring in approximately 2% of the population. It is a small pouch or sac that forms on the wall of the small intestine, specifically the ileum, and is present from birth. This diverticulum is a remnant of the omphalomesenteric duct (also called the vitelline duct), which normally disappears during the seventh week of fetal development. When this duct fails to completely obliterate, it results in Meckel's diverticulum.

Named after German anatomist Johann Friedrich Meckel who first described it in 1809, this condition is characterized by the famous "rule of twos": it occurs in about 2% of the population, is typically located about 2 feet from the ileocecal valve, is usually about 2 inches long, often contains 2 types of ectopic tissue (gastric and pancreatic), is 2 times more common in males, and most commonly presents with symptoms before age 2. However, many people with Meckel's diverticulum remain asymptomatic throughout their lives and may never know they have it.

While most individuals with Meckel's diverticulum experience no problems, complications can occur in about 4-6% of cases. These complications can be serious and include bleeding, obstruction, inflammation (diverticulitis), and perforation. The presence of ectopic gastric tissue, found in about 50% of cases, is particularly significant as it can produce acid that leads to ulceration and bleeding. When symptomatic, Meckel's diverticulum most commonly presents in childhood, but complications can occur at any age, making it an important consideration in the differential diagnosis of various gastrointestinal conditions.

The Rule of Twos

  • Occurs in ~2% of the population
  • Located ~2 feet from the ileocecal valve
  • Usually ~2 inches in length
  • Contains 2 types of ectopic tissue (gastric and pancreatic)
  • 2 times more common in males
  • Most symptomatic before age 2

Symptoms

Most people with Meckel's diverticulum have no symptoms and live their entire lives unaware of its presence. However, when complications occur, symptoms can vary depending on the type of complication and the patient's age. Children and adults may present differently.

Bleeding Symptoms (Most Common in Children)

Rectal bleeding

Painless, bright red or maroon blood in stool, often described as "currant jelly"

Melena

Black, tarry stools indicating digested blood from upper GI bleeding

Anemia symptoms

Fatigue, pallor, weakness from chronic blood loss

Dizziness

Lightheadedness from significant blood loss or anemia

Obstruction Symptoms

Abdominal pain

Crampy, intermittent pain that may become constant with complete obstruction

Vomiting

Initially food contents, progressing to bilious (green) vomiting

Abdominal distension

Swelling of the abdomen due to trapped gas and fluid

Constipation

Inability to pass stool or gas with complete obstruction

Diverticulitis Symptoms

  • Lower abdominal pain: Often mimics appendicitis but on the left side
  • Fever: Low-grade to high fever depending on severity
  • Nausea and vomiting: Due to inflammation and irritation
  • Tenderness: Point tenderness in the periumbilical or right lower quadrant
  • Loss of appetite: Common with inflammatory conditions
  • Change in bowel habits: Diarrhea or constipation

Perforation Symptoms (Emergency)

  • Sudden, severe abdominal pain
  • Rigid, board-like abdomen
  • High fever and chills
  • Signs of shock (rapid pulse, low blood pressure)
  • Rebound tenderness
  • Absent bowel sounds

Age-Related Presentations

  • Infants (0-2 years):
    • Painless rectal bleeding most common
    • Intestinal obstruction from intussusception
    • Volvulus (twisting of intestine)
  • Children (2-10 years):
    • Rectal bleeding remains common
    • Abdominal pain becoming more prominent
    • May present like appendicitis
  • Adults:
    • Diverticulitis more common than bleeding
    • Intestinal obstruction
    • Often incidental finding during surgery

Causes

Meckel's diverticulum is a congenital condition resulting from incomplete obliteration of the omphalomesenteric duct during fetal development. Understanding its embryological origin and associated factors helps explain its clinical manifestations.

Embryological Development

  • Normal development:
    • Omphalomesenteric duct connects yolk sac to midgut in early embryo
    • Provides nutrition before placental circulation established
    • Normally obliterates by 7th-8th week of gestation
    • Complete resorption leaves no remnant
  • Abnormal persistence:
    • Failure of complete duct obliteration
    • Leaves a diverticulum on antimesenteric border of ileum
    • Contains all layers of intestinal wall (true diverticulum)
    • May retain connection to umbilicus in rare cases

Types of Omphalomesenteric Duct Remnants

  • Meckel's diverticulum (90%): Most common type
  • Umbilical sinus: Opening at umbilicus with discharge
  • Omphalomesenteric cyst: Cyst along the duct path
  • Fibrous cord: Connecting intestine to umbilicus
  • Complete fistula: Patent connection from intestine to umbilicus

Ectopic Tissue

  • Gastric mucosa (50-60%):
    • Most common ectopic tissue
    • Produces acid leading to ulceration
    • Responsible for bleeding complications
    • Can be detected by technetium scan
  • Pancreatic tissue (5-16%):
    • Second most common
    • May cause inflammation
    • Can lead to diverticulitis
  • Other tissues (rare):
    • Colonic mucosa
    • Duodenal mucosa
    • Biliary tissue
    • Combinations possible

Factors Influencing Complications

  • Anatomical factors:
    • Length of diverticulum
    • Width of base
    • Presence of fibrous bands
    • Blood supply adequacy
  • Tissue factors:
    • Type of ectopic tissue present
    • Amount of acid-producing tissue
    • Inflammatory changes

Risk Factors

While Meckel's diverticulum is congenital and cannot be prevented, certain factors increase the risk of developing complications:

Demographic Factors

  • Gender: Males 2-3 times more likely to have symptomatic disease
  • Age:
    • Highest complication rate in first 2 years of life
    • 60% of complications occur before age 10
    • Risk decreases with age but never reaches zero
  • Family history: Slightly increased risk with affected family members

Anatomical Risk Factors for Complications

  • Presence of ectopic gastric mucosa: Major risk for bleeding
  • Long diverticulum: Increased risk of volvulus and obstruction
  • Narrow base: Higher risk of inflammation and perforation
  • Fibrous bands: Risk of intestinal obstruction
  • Mesodiverticular band: Can cause internal hernia

Clinical Risk Factors

  • H. pylori infection: May increase bleeding risk in gastric mucosa
  • NSAID use: Can precipitate bleeding in susceptible individuals
  • Inflammatory conditions: May trigger diverticulitis
  • Previous abdominal surgery: Adhesions may increase obstruction risk

Associated Conditions

  • Other congenital anomalies (10-15% association)
  • Cardiovascular malformations
  • Central nervous system anomalies
  • Urogenital abnormalities
  • Omphalocele
  • Esophageal atresia

Diagnosis

Diagnosing Meckel's diverticulum can be challenging because it often mimics other conditions. Many cases are discovered incidentally during surgery for other reasons. When symptomatic, specific diagnostic tests can help identify this condition.

Clinical Assessment

  • History:
    • Age of patient and symptom onset
    • Character of rectal bleeding (painless vs painful)
    • Pattern of abdominal pain
    • Previous similar episodes
    • Family history of GI conditions
  • Physical examination:
    • Vital signs (evidence of bleeding or infection)
    • Abdominal examination
    • Rectal examination
    • Signs of anemia
    • Evidence of obstruction

Laboratory Tests

  • Complete blood count: Check for anemia, leukocytosis
  • Metabolic panel: Electrolyte imbalances from vomiting
  • Coagulation studies: If significant bleeding
  • Inflammatory markers: CRP, ESR if diverticulitis suspected
  • Stool tests: Occult blood, rule out infection

Imaging Studies

  • Technetium-99m pertechnetate scan (Meckel's scan):
    • Gold standard for detecting gastric mucosa
    • 85-95% sensitivity in children
    • Lower sensitivity in adults
    • False positives: intussusception, duplications
    • Requires fasting and medication preparation
  • CT scan with contrast:
    • Better for complications (obstruction, perforation)
    • May show blind-ending pouch
    • Can detect inflammation
    • Useful in emergency settings
  • Ultrasound:
    • May show fluid-filled structure
    • Good for detecting intussusception
    • Operator dependent
    • Limited by bowel gas
  • Capsule endoscopy:
    • Can visualize diverticulum opening
    • Useful for obscure GI bleeding
    • Risk of capsule retention
  • Double-balloon enteroscopy:
    • Direct visualization possible
    • Therapeutic intervention capability
    • Invasive and time-consuming

Surgical Findings

  • Often diagnosed during exploratory laparotomy/laparoscopy
  • Found 40-100 cm proximal to ileocecal valve (average 60 cm)
  • Antimesenteric location characteristic
  • May have separate blood supply
  • Palpable thickening if ectopic tissue present

Differential Diagnosis

  • In children:
    • Intussusception
    • Appendicitis
    • Intestinal duplication
    • Polyps
    • Inflammatory bowel disease
  • In adults:
    • Peptic ulcer disease
    • Diverticulitis
    • Crohn's disease
    • Small bowel tumors
    • Angiodysplasia

Treatment Options

Treatment of Meckel's diverticulum depends on whether it's symptomatic or discovered incidentally. Symptomatic cases require surgical intervention, while management of incidental findings remains controversial.

Symptomatic Meckel's Diverticulum

  • Surgical resection indicated for:
    • Any complication (bleeding, obstruction, perforation)
    • Recurrent symptoms
    • Failed medical management
  • Surgical options:
    • Diverticulectomy:
      • Simple excision of diverticulum
      • Suitable for uncomplicated cases
      • Preserves bowel length
      • Risk of leaving ectopic tissue at base
    • Segmental ileal resection:
      • Preferred for complicated cases
      • Removes all ectopic tissue
      • End-to-end anastomosis
      • Lower recurrence risk
    • Wedge resection:
      • For small-based diverticula
      • Preserves more bowel
      • Careful margin assessment needed
  • Surgical approach:
    • Laparoscopic (preferred when feasible)
    • Open surgery for complications
    • Emergency surgery for perforation/severe bleeding

Incidental Meckel's Diverticulum

  • Factors favoring prophylactic removal:
    • Age <50 years
    • Male gender
    • Diverticulum >2 cm length
    • Palpable ectopic tissue
    • Fibrous bands present
    • Narrow base
    • Signs of previous inflammation
  • Factors against removal:
    • Age >50 years
    • Female gender
    • Short, wide-based diverticulum
    • No palpable abnormality
    • High surgical risk patient

Medical Management

  • Supportive care for bleeding:
    • IV fluid resuscitation
    • Blood transfusion if needed
    • Proton pump inhibitors
    • H2 receptor blockers
  • Obstruction management:
    • NPO (nothing by mouth)
    • Nasogastric decompression
    • IV fluids and electrolytes
    • Antibiotics if perforation suspected

Post-Operative Care

  • Gradual diet advancement
  • Pain management
  • Early ambulation
  • Monitor for complications
  • Typical hospital stay 2-5 days
  • Return to normal activities in 2-4 weeks

Complications of Surgery

  • Early complications:
    • Bleeding
    • Anastomotic leak
    • Wound infection
    • Ileus
  • Late complications:
    • Adhesive obstruction
    • Incisional hernia
    • Short bowel syndrome (rare)

Prevention

Since Meckel's diverticulum is a congenital condition, it cannot be prevented. However, complications can potentially be minimized through awareness and appropriate management:

Early Recognition

  • High index of suspicion in:
    • Young children with painless rectal bleeding
    • Recurrent abdominal pain of unclear etiology
    • Family history of Meckel's diverticulum
    • Unexplained iron deficiency anemia
  • Prompt evaluation:
    • Don't dismiss intermittent symptoms
    • Consider Meckel's in differential diagnosis
    • Early imaging when indicated

Risk Reduction Strategies

  • For known Meckel's diverticulum:
    • Discuss prophylactic removal with surgeon
    • Regular follow-up if not removed
    • Awareness of warning symptoms
    • Medical alert information
  • General measures:
    • Avoid NSAIDs if history of GI bleeding
    • Maintain good bowel habits
    • Stay hydrated
    • High-fiber diet to prevent constipation

Education

  • Family awareness if diagnosed
  • Understanding of symptoms requiring immediate care
  • Knowledge of potential complications
  • Importance of mentioning to healthcare providers

When to See a Doctor

Meckel's diverticulum complications can be serious and require prompt medical attention. Knowing when to seek help is crucial:

Seek Emergency Care (Call 911) For:

  • Large amount of rectal bleeding or blood in stool
  • Severe abdominal pain, especially if sudden onset
  • Signs of shock (dizziness, rapid pulse, cold sweats, confusion)
  • Rigid or board-like abdomen
  • High fever with abdominal pain
  • Persistent vomiting with inability to keep fluids down
  • No bowel movements or gas passage with distended abdomen

See Your Doctor Promptly For:

  • Recurring episodes of painless rectal bleeding
  • Blood in stool, even if small amounts
  • Unexplained abdominal pain lasting more than a few hours
  • Changes in bowel habits with cramping
  • Persistent nausea or vomiting
  • Signs of anemia (fatigue, pallor, weakness)
  • Intermittent abdominal pain in children

For Parents: Watch for These Signs in Children:

  • Bright red or maroon-colored stools
  • Crying with abdominal pain
  • Refusing to eat or drink
  • Lethargy or unusual irritability
  • Pale appearance
  • Vomiting, especially if green (bilious)

What to Tell Your Doctor:

  • Character and duration of symptoms
  • Any blood in stool (color, amount)
  • Pattern of abdominal pain
  • Associated symptoms (fever, vomiting)
  • Previous similar episodes
  • Family history of GI problems
  • Current medications

References

  1. Sagar J, Kumar V, Shah DK. Meckel's diverticulum: a systematic review. Journal of the Royal Society of Medicine. 2006;99(10):501-505.
  2. Hansen CC, Søreide K. Systematic review of epidemiology, presentation, and management of Meckel's diverticulum in the 21st century. Medicine. 2018;97(35):e12154.
  3. Lequet J, et al. Meckel's diverticulum in the adult. Journal of Visceral Surgery. 2017;154(4):253-259.
  4. Kuru S, et al. Mesodiverticular band of Meckel's diverticulum as a rare cause of small bowel obstruction: Case report and review of the literature. Viszeralmedizin. 2013;29(6):401-405.
  5. Kotecha M, et al. The role of laparoscopy in the management of Meckel's diverticulum in children: A systematic review. Pediatric Surgery International. 2012;28(3):245-249.
  6. Park JJ, et al. Meckel Diverticulum: The Mayo Clinic Experience with 1476 Patients (1950-2002). Annals of Surgery. 2005;241(3):529-533.

Medical Disclaimer: This information is for educational purposes only and should not replace professional medical advice. Always consult with a qualified healthcare provider for diagnosis and treatment of medical conditions.