Ileus

Overview

Ileus is a condition characterized by a lack of movement in the intestines that prevents the normal passage of food, fluid, and gas through the digestive system. Unlike mechanical bowel obstruction where there is a physical blockage, ileus represents a functional problem where the intestinal muscles fail to contract properly. This condition is also known as paralytic ileus, adynamic ileus, or intestinal pseudo-obstruction, reflecting the fact that the bowel appears obstructed but without any mechanical cause.

The normal functioning of the intestines depends on coordinated muscular contractions called peristalsis, which move contents through the digestive tract. In ileus, these contractions are significantly reduced or absent, causing a backup of intestinal contents. This can lead to abdominal distension, pain, nausea, and vomiting. While ileus can affect any part of the gastrointestinal tract, it most commonly involves the small intestine. The condition is particularly common after abdominal surgery, affecting up to 10-15% of patients undergoing major abdominal procedures.

Ileus can be a serious condition if not properly managed, as the accumulation of intestinal contents can lead to complications such as bacterial overgrowth, electrolyte imbalances, and in severe cases, intestinal perforation. However, with appropriate treatment, most cases of ileus resolve within a few days. Understanding the difference between ileus and mechanical obstruction is crucial for proper management, as the treatment approaches differ significantly. While mechanical obstruction often requires surgical intervention, ileus is typically managed conservatively with supportive care.

Symptoms

The symptoms of ileus can range from mild discomfort to severe abdominal distress. They typically develop gradually and may fluctuate in intensity.

Common Gastrointestinal Symptoms

Bowel-Related Symptoms

• Constipation - inability to pass stool
• Inability to pass gas (flatus)
• Abdominal distension or bloating
• Anal pain from straining
• Absence of bowel sounds (detected by healthcare provider)
• Feeling of fullness even without eating

Associated Symptoms

• Vomiting - may contain bile or fecal material in severe cases
• Headache - often from dehydration
• Loss of appetite
• Dehydration symptoms (dry mouth, decreased urination)
• Fever (if infection develops)
• Tachycardia (rapid heart rate)

Paradoxical Symptoms

Some patients may experience:

• Diarrhea - overflow diarrhea around impacted stool
• Alternating constipation and diarrhea
• Passage of small amounts of liquid stool

Severity Indicators

Seek immediate medical attention for:

• Severe, persistent abdominal pain
• Vomiting that prevents keeping fluids down
• Signs of peritonitis (rigid abdomen, high fever)
• Complete inability to pass gas or stool for more than 3 days
• Signs of shock (low blood pressure, rapid pulse, confusion)

Causes

Ileus can result from various factors that disrupt the normal nerve and muscle function of the intestines. Understanding these causes is essential for proper treatment and prevention.

Postoperative Ileus

The most common cause, occurring after:

• Abdominal surgery (particularly bowel resection)
• Pelvic surgery
• Spine surgery
• Any procedure requiring general anesthesia
• Manipulation of intestines during surgery

Medications

• Opioid pain medications: Major cause of drug-induced ileus
• Anticholinergics: Reduce bowel motility
• Antidepressants: Particularly tricyclics
• Antipsychotics: Can affect gut motility
• Calcium channel blockers: May slow intestinal movement
• General anesthetics: Temporary paralysis of bowel

Metabolic and Electrolyte Disturbances

• Hypokalemia (low potassium)
• Hyponatremia (low sodium)
• Hypomagnesemia (low magnesium)
• Hypocalcemia (low calcium)
• Uremia (kidney failure)
• Diabetic ketoacidosis
• Hypothyroidism

Inflammatory Conditions

• Peritonitis (inflammation of abdominal lining)
• Appendicitis
• Pancreatitis
• Cholecystitis
• Inflammatory bowel disease flare
• Diverticulitis

Other Medical Conditions

• Infections: Gastroenteritis, sepsis
• Neurological: Parkinson's disease, multiple sclerosis
• Vascular: Mesenteric ischemia
• Trauma: Spinal cord injury, head injury
• Heart conditions: Myocardial infarction
• Lung conditions: Pneumonia, especially lower lobe

Mechanical Factors

While not true ileus, these can mimic symptoms:

• Adhesions from previous surgery
• Hernias
• Tumors
• Volvulus (twisted bowel)
• Intussusception

Risk Factors

Certain factors increase the likelihood of developing ileus:

Surgical Risk Factors

• Recent abdominal or pelvic surgery
• Prolonged surgical procedures
• Emergency surgery
• Multiple previous abdominal surgeries
• Open surgery versus laparoscopic
• Extensive bowel manipulation

Medical Conditions

• Diabetes mellitus (diabetic gastroparesis)
• Chronic kidney disease
• Heart failure
• Chronic lung disease
• Neurological disorders
• Autoimmune conditions

Demographic Factors

• Age: Elderly at higher risk
• Immobility: Bedridden patients
• Hospitalization: ICU patients particularly vulnerable
• Malnutrition: Poor nutritional status

Medication Use

• Chronic opioid use
• Multiple medications affecting gut motility
• Recent chemotherapy
• Radiation therapy to abdomen

Lifestyle Factors

• Sedentary lifestyle
• Poor dietary habits
• Chronic constipation
• Dehydration
• Smoking

Diagnosis

Diagnosing ileus requires distinguishing it from mechanical bowel obstruction and identifying the underlying cause.

Clinical Assessment

• Detailed medical history including recent surgery or illness
• Medication review
• Physical examination of abdomen
• Auscultation for bowel sounds (typically absent or hypoactive)
• Assessment of abdominal distension
• Digital rectal examination

Laboratory Tests

• Complete blood count: Check for infection or anemia
• Electrolyte panel: Identify imbalances
• Kidney function tests: BUN, creatinine
• Liver function tests: If hepatic cause suspected
• Thyroid function: If hypothyroidism suspected
• Inflammatory markers: CRP, ESR

Imaging Studies

Plain Abdominal X-ray

• First-line imaging study
• Shows dilated bowel loops
• Air-fluid levels throughout bowel
• Gas pattern in both small and large bowel
• No transition point (unlike mechanical obstruction)

CT Scan

• More detailed evaluation
• Rules out mechanical obstruction
• Identifies complications
• Can show underlying causes

Contrast Studies

• Water-soluble contrast enema
• Upper GI series with small bowel follow-through
• Can be therapeutic as well as diagnostic

Differential Diagnosis

Conditions to rule out include:

• Mechanical bowel obstruction
• Ogilvie syndrome (colonic pseudo-obstruction)
• Chronic intestinal pseudo-obstruction
• Gastroparesis
• Mesenteric ischemia

Treatment Options

Treatment of ileus focuses on supportive care while addressing the underlying cause and allowing bowel function to return.

Conservative Management

Bowel Rest

• NPO (nothing by mouth) initially
• Gradual introduction of clear liquids
• Progressive diet advancement as tolerated
• Avoid foods that increase gas production

Nasogastric Decompression

• NG tube placement for stomach decompression
• Reduces nausea and vomiting
• Prevents aspiration
• May provide symptomatic relief

Fluid and Electrolyte Management

• IV fluid resuscitation
• Correction of electrolyte imbalances
• Potassium replacement often crucial
• Monitoring of fluid balance
• Daily electrolyte checks

Medication Management

Medications to Avoid

• Opioid analgesics (use alternatives)
• Anticholinergic medications
• Medications that slow gut motility

Prokinetic Agents

• Metoclopramide: Enhances upper GI motility
• Erythromycin: Motilin receptor agonist
• Neostigmine: For colonic ileus (Ogilvie syndrome)
• Methylnaltrexone: For opioid-induced ileus

Supportive Measures

• Early ambulation: Stimulates bowel function
• Gum chewing: May promote bowel motility
• Coffee: Can stimulate bowel activity
• Abdominal massage: Gentle circular motions
• Heat application: Heating pad for comfort

Advanced Interventions

• Colonoscopic decompression: For Ogilvie syndrome
• Rectal tube: For gas decompression
• Epidural anesthesia: May help postoperative ileus
• Acupuncture: Some evidence for benefit

Surgical Intervention

Surgery is rarely needed but may be required for:

• Failed conservative management
• Signs of perforation
• Ischemic bowel
• Cecal diameter >12 cm (risk of perforation)

Nutritional Support

• Parenteral nutrition if prolonged ileus
• Gradual diet progression when resolved
• Low-residue diet initially
• Adequate hydration maintenance

Prevention

While not all cases of ileus can be prevented, several strategies can reduce the risk, especially in high-risk situations.

Perioperative Prevention

• Minimally invasive surgical techniques when possible
• Epidural analgesia instead of opioids
• Early postoperative mobilization
• Gum chewing after surgery
• Avoid routine nasogastric decompression
• Early feeding protocols
• Limiting opioid use

Medication Management

• Use non-opioid pain management when possible
• Prophylactic laxatives with opioid therapy
• Regular review of medications affecting bowel function
• Consider opioid-sparing techniques

Lifestyle Modifications

• Regular physical activity
• Adequate fiber intake
• Proper hydration
• Avoid prolonged bed rest
• Manage chronic constipation
• Stress management

Medical Optimization

• Control diabetes effectively
• Treat thyroid disorders
• Maintain electrolyte balance
• Address nutritional deficiencies
• Manage chronic conditions that affect gut motility

Enhanced Recovery Protocols

For surgical patients:

• Preoperative counseling
• Avoid prolonged fasting
• Carbohydrate loading before surgery
• Goal-directed fluid therapy
• Multimodal analgesia
• Early discontinuation of urinary catheters

When to See a Doctor

Ileus can be a serious condition requiring medical attention. Knowing when to seek help is crucial.

Seek Immediate Emergency Care

• Severe abdominal pain that suddenly worsens
• Signs of peritonitis (rigid, tender abdomen)
• High fever with abdominal symptoms
• Vomiting blood or dark material
• Signs of shock (rapid pulse, low blood pressure, confusion)
• Complete inability to pass gas or stool for several days

See a Doctor Promptly For

• Persistent nausea and vomiting
• Abdominal distension that worsens
• Inability to keep fluids down
• No bowel movement for more than 3 days
• Abdominal pain lasting more than a few hours
• Recent surgery with concerning symptoms

Schedule an Appointment For

• Chronic constipation
• Recurring episodes of ileus
• Medication side effects affecting bowel function
• Concerns about bowel habits
• Need for preventive strategies

High-Risk Situations

Be especially vigilant if you have:

• Recent abdominal surgery
• History of bowel obstruction
• Chronic opioid use
• Diabetes or other conditions affecting nerves
• Elderly age with multiple medical conditions

Related Conditions

Frequently Asked Questions