What is colonic ileus?

Colonic Ileus: Definition and Management

Colonic ileus is a form of adynamic (paralytic) ileus characterized by functional obstruction of the colon without mechanical blockage, resulting from uncoordinated or attenuated intestinal muscle contractions that can mimic true intestinal obstruction. 1, 2

Pathophysiology

• Colonic ileus results from impaired colonic motility due to increased sympathetic activity that inhibits bowel function 1
• It presents with massive colonic dilatation with variable, moderate small bowel dilatation 2
• The condition can lead to increased intra-abdominal pressure, intestinal wall ischemia, and potential perforation if not promptly managed 3

Causes

• Postoperative state, particularly after spinal surgeries like laminectomy 1
• Metabolic disorders and electrolyte abnormalities 2
• Medications that inhibit intestinal motility 2
• Severe illnesses and extensive surgeries 2
• Neurological conditions affecting autonomic nervous system 4

Clinical Presentation

• Abdominal distention is a prominent feature 5
• Decreased or absent bowel sounds 4
• Nausea and vomiting 2
• Inability to pass flatus or stool 4
• Severe cecal dilation on imaging (often >12 cm) 1, 5

Diagnosis

• Plain abdominal radiographs showing dilated colon without mechanical obstruction 5
• CT scan to exclude mechanical obstruction 6
• Laboratory tests to identify electrolyte abnormalities (particularly potassium and magnesium) 6
• Careful monitoring of cecal diameter (critical threshold >12 cm) 1

Management

Initial Management

• Administer isotonic intravenous fluids to correct dehydration and electrolyte imbalances 6
• Place nasogastric tube for decompression in patients with severe abdominal distention or vomiting 6
• Correct electrolyte abnormalities, particularly potassium and magnesium, which affect intestinal motility 6
• Administer subcutaneous heparin to reduce thromboembolism risk in prolonged immobility 6

Supportive Care

• Maintain nil per os (NPO) status initially until bowel function returns 6
• Provide early mobilization to stimulate bowel function 6
• Avoid fluid overloading as it can worsen intestinal edema and prolong ileus 6
• Provide nutritional support if ileus is prolonged 6

Pharmacologic Interventions

• Consider alvimopan to accelerate gastrointestinal recovery when opioid analgesia is necessary 6
• Avoid medications that can worsen ileus, such as anticholinergics and opioids 6
• Consider neostigmine (an anticholinesterase) for pharmacologic colonic decompression 2
• Oral magnesium oxide may promote bowel function once oral intake is resumed 6

Invasive Interventions

• Colonoscopic decompression may be necessary for persistent distention 2, 3
• Colonic tube placement after decompressive colonoscopy can help reduce intestinal dilatation 3
• Surgical intervention (cecostomy or other decompressive procedures) is indicated if cecal diameter exceeds 12 cm despite conservative management 1
• In severe cases with abdominal compartment syndrome, decompressive laparotomy may be necessary 3

Monitoring and Follow-up

• Monitor for signs of bowel function return, including passage of flatus and bowel sounds 6
• Resume oral intake gradually once bowel function returns, starting with clear liquids 6
• Carefully monitor cecal diameter through serial imaging 1, 5

Prevention Strategies

• Minimize opioid use for pain control 6
• Implement early mobilization after surgery or illness 6
• Maintain proper fluid balance without overload 6
• Consider chewing gum to help stimulate bowel function through cephalic-vagal stimulation 6

Complications

• Intestinal bacterial overgrowth with potential bacterial translocation 3
• Systemic inflammatory response syndrome due to intestinal wall inflammation 3
• Abdominal compartment syndrome (intra-abdominal pressure >20-25 mmHg with systemic consequences) 3
• Cecal perforation, which can be life-threatening 1, 5