What is the assessment and plan for a patient with a markedly dilated cecum measuring 15.4 cm secondary to fecal impaction causing acute colonic obstruction in the setting of chronic slow‑transit constipation?

Assessment and Management of Dilated Cecum (15.4 cm) from Fecal Impaction with Chronic Slow-Transit Constipation

This patient requires urgent surgical consultation and immediate decompression because cecal diameter >12 cm carries high risk of perforation and mortality, and the underlying chronic slow-transit constipation makes conservative management likely to fail. 1, 2

Immediate Assessment

Critical Risk Stratification

• Examine for peritoneal signs (rebound tenderness, guarding, rigidity), fever, hypotension, tachycardia—any of these mandate immediate surgery 1
• Obtain serum lactate and complete blood count—elevated lactate or marked leukocytosis indicate bowel ischemia requiring emergency operative intervention 1, 3
• Review CT imaging to confirm no mechanical obstruction and assess for signs of ischemia (reduced bowel wall enhancement, pneumatosis, mesenteric venous gas, free air) 1, 3
• Serial abdominal examinations are essential as clinical deterioration can occur rapidly 1

Key Diagnostic Distinction

This presentation represents acute-on-chronic colonic pseudo-obstruction (Ogilvie syndrome) precipitated by severe fecal impaction in the setting of known slow-transit constipation, rather than mechanical obstruction 1, 2. The cecal diameter of 15.4 cm far exceeds the critical 12 cm threshold where perforation risk escalates dramatically 1, 2.

Management Algorithm

If Hemodynamically Stable WITHOUT Peritonitis

Step 1: Immediate Conservative Measures

• NPO status with nasogastric tube decompression to prevent aspiration and reduce proximal bowel distension 3
• Aggressive IV crystalloid resuscitation to correct dehydration and electrolyte abnormalities, particularly potassium and magnesium 4, 3
• Discontinue all medications that impair colonic motility (opioids, anticholinergics, calcium channel blockers, antipsychotics if psychiatrically feasible) 1, 3

Step 2: Distal Fecal Disimpaction (if no contraindications)

• Digital rectal examination to confirm distal impaction 4
• Manual fragmentation and extraction of accessible stool 4, 5
• Water or oil retention enemas followed by suppositories to facilitate passage 4
• Contraindications: neutropenia, thrombocytopenia, recent pelvic surgery or radiation, severe colitis 4

Step 3: Proximal Softening (only after partial distal clearance)

• Polyethylene glycol (PEG) solutions with electrolytes administered orally or via nasogastric tube to soften and wash out proximal impaction 4, 5
• Water-soluble contrast (Gastrografin) 50-150 mL can serve dual diagnostic/therapeutic role after adequate gastric decompression 3, 6
• Critical timing: Administer only after 48 hours of rehydration and gastric decompression to avoid aspiration pneumonia and hypovolemic shock 3

Step 4: Endoscopic Decompression

• Colonoscopic decompression should be attempted if cecal diameter remains >12 cm despite conservative measures 1, 2
• This is preferred over surgery in stable patients to avoid surgical morbidity in the setting of chronic constipation 1
• Tube cecostomy may be performed endoscopically or radiologically if colonoscopic decompression fails 4, 2

Step 5: Monitoring and Decision Points

• Serial imaging to monitor cecal diameter—persistent >12 cm despite intervention warrants surgical consultation 1
• 48-72 hour observation window is the maximum safe period for conservative management 3
• Repeat CT at 48-72 hours if no clinical improvement to reassess for evolving complications 3

If Hemodynamically Unstable OR Peritonitis Present

Immediate surgical intervention is mandatory 1, 3

Surgical options:

• Right hemicolectomy is definitive treatment if perforation, necrosis, or widely scattered areas of ischemia are present 7, 2
• Tube cecostomy may be curative even with taenia splitting if no perforation or extensive necrosis 2
• Laparoscopic approach is feasible only in stable patients without peritonitis; open surgery is required for instability or perforation 8, 3
• Avoid primary anastomosis in the setting of contamination, hemodynamic instability, or poor nutritional status—create a stoma instead 8

Post-Treatment Management

Immediate Post-Resolution

• Colonic evaluation with flexible sigmoidoscopy or colonoscopy after impaction resolves to exclude underlying structural pathology (stricture, malignancy) 5, 6
• Assess for stercoral ulcers which can lead to delayed perforation 4, 6

Long-Term Prevention Strategy

This is critical because recurrence is common and the underlying slow-transit constipation persists 6, 9

• Scheduled laxative regimen: Osmotic laxatives (PEG, lactulose) or stimulant laxatives (senna, bisacodyl) are preferred 4, 1
• Avoid bulk laxatives (psyllium) as they can worsen obstruction in slow-transit constipation 4
• Increase dietary fiber to 30 grams/day and ensure adequate hydration 1, 6, 9
• Reduce or eliminate constipating medications permanently if possible 1, 3
• Consider prokinetic agents for chronic slow-transit constipation 6
• Antegrade continence enema (ACE) or cecostomy button may be considered for refractory cases to prevent future episodes 4

Critical Pitfalls to Avoid

• Do not delay surgical consultation when cecal diameter exceeds 12 cm—mortality increases dramatically with perforation 1, 2
• Do not administer PEG or water-soluble contrast before distal disimpaction and adequate rehydration—this risks aspiration and hypovolemic shock 3, 6
• Do not use enemas if patient has neutropenia, thrombocytopenia, or recent pelvic surgery 4
• Do not extend conservative management beyond 72 hours without repeat imaging and surgical reassessment 3
• Do not overlook the need for long-term bowel regimen—recurrence is the rule without preventive therapy 6, 9
• Do not assume this is simple constipation—the cecal diameter indicates life-threatening colonic distension requiring aggressive intervention 1, 2