Epidemiology

XXXX

• xxx

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Etiologic/Risk Factors

• Aerophagia
• Electrolyte Abnormality
  • Physiology
    • XXXX
• Medications Which Impair Colonic Motility
  • Physiology
    • XXXX
• Scleroderma (see Scleroderma)
  • Physiology
    • Due to Colonic Dysmotility
• Sepsis (see Sepsis)
  • Physiology
    • XXXX

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Physiology

• Acute Marked Colonic Distention in the Absence of Defined Mechanical Pathology
  • May be referred to as “colonic Ileus”: however, pseudo-obstruction is limited to the colon alone (while ileus affects both the small bowel and the colon)
  • Pseudo-obstruction may affect the right colon
  • Note: this is distinct from chronic intestinal pseudo-obstruction (see Chronic Intestinal Pseudo-Obstruction)

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Diagnosis

Kidney-Ureter-Bladder X-Ray (see xxxx)

• Findings
  • Isolated Proximal Colonic Dilatation

Abdominal/Pelvic Computed Tomography (CT) (see Abdominal-Pelvic Computed Tomography)

• Findings
  • Typically Isolated Proximal Colonic Dilatation

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Clinical Differentiation of Similar Entities

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Clinical Manifestations

Gastrointestinal Manifestations

Abdominal Distention (see Abdominal Distention)

• Clinical
  • Abdominal Distention is the Main Clinical Feature (and May Mimic that of Bowel Obstruction)
  • Time Course
    • Usually Develops of 3-7 Days (But May Develop Over 1-2 Days in Some Cases)
  • Bowel Sounds are Present in 90% of Cases
  • Tympanitic Abdomen is Characteristic

Constipation (see Constipation)

• Epidemiology
  • Constipation Occurs in 50% of Cases

Diarrhea (see Diarrhea)

• Epidemiology
  • Diarrhea Occurs in 40% of Cases

Mild Abdominal Pain (see Abdominal Pain)

• Epidemiology
  • Mild Abdominal Pain Occurs in 80% of Cases

Nausea/Vomiting (see see Nausea and Vomiting)

• Epidemiology
  • Nausea/Vomiting Occurs in 60% of Cases

Complications

• Severe Abdominal Pain/Tenderness: due to colonic ischemia/peritonitis
• Colonic Ischemia (see Colonic Ischemia)
• Colonic Perforation (see Colonic Perforation)
• Fever (see Fever): due to colonic ischemia/peritonitis
• Peritonitis (see Peritonitis): due to colonic ischemia/peritonitis
  • Peritoneal Signs
    • Guarding
    • Rebound Tenderness
    • Rigidity

Pulmonary Manifestations

Dyspnea (see Dyspnea)

• Epidemiology
  • Dyspnea May Rarely Occur
• Mechanism
  • Abdominal Distention

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Treatment

Medical Therapy

• Colonoscopic Decompression: effective
• Correction of Electrolyte Abnormalities
• Discontinuation of Medications Which Impair Bowel Motility
• Intravenous Fluid Hydration
• Nasogastric Tube: recommended
• Neostigmine (see Neostigmine)
  • Administration: 2.5 mg IV over 3 min (with cardiac monitoring for bradycardia)
  • Adverse Effects
    • Sinus Bradycardia (see Sinus Bradycardia): treat with atropine (see Atropine)
  • Clinical Efficacy: may result in resolution of pseudo-obstruction within 10-30 min
• Rectal Tube: recommended

Surgical Therapy

• Laparotomy with Bowel Resection/Ostomy: considered a last resort, but may be required in cases with bowel ischemia/peritonitis

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Prognosis

Mortality Rate

• Mortality Rate is 50% in Cases with Colonic Ischemia/Perforation

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References

General

• Clinical Practice Guidelines for Colon Volvulus and Acute Colonic Pseudo-Obstruction. Dis Colon Rectum. 2016;59(7):589 [MEDLINE]
• American Society for Gastrointestinal Endoscopy guideline on the role of endoscopy in the management of acute colonic pseudo-obstruction and colonic volvulus. Gastrointest Endosc. 2020;91(2):228 [MEDLINE]
• The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Management of Colonic Volvulus and Acute Colonic Pseudo-Obstruction. Dis Colon Rectum. 2021;64(9):1046 [MEDLINE]