What are the treatment options for a patient with right-sided constipation or bowel obstruction?

Treatment of Right-Sided Constipation or Bowel Obstruction

For right-sided colon obstruction due to malignancy, right colectomy with primary ileocolic anastomosis is the preferred surgical treatment in stable patients, while unstable patients require right colectomy with terminal ileostomy. 1

Initial Assessment: Rule Out Complete Obstruction First

Before any laxative therapy, you must immediately:

• Discontinue all oral laxatives and obtain plain abdominal radiography or CT scan to rule out complete bowel obstruction or fecal impaction 2
• Perform digital rectal examination to assess for fecal impaction—hard stool requires manual disimpaction or enema rather than oral laxatives 2
• Assess for peritoneal signs indicating perforation or ischemia 2

Critical pitfall: Never give oral laxatives in the setting of complete bowel obstruction—this can worsen the obstruction and increase perforation risk. 2

Management Algorithm Based on Clinical Presentation

If Mechanical Obstruction is Present (Right-Sided)

For Stable Patients:

• Right colectomy with primary ileocolic anastomosis is the treatment of choice 1
• A terminal ileostomy with colonic fistula is a valid alternative when primary anastomosis is considered unsafe 1
• For unresectable right-sided colon cancer, perform side-to-side anastomosis between terminal ileum and transverse colon (internal bypass), or fashion a loop ileostomy 1
• Decompressive cecostomy should be abandoned 1

For Unstable Patients (pH <7.2, temp <35°C, BE <-8, coagulopathy, or sepsis/septic shock):

• Right colectomy with terminal ileostomy is the procedure of choice 1
• Severely unstable patients should be treated with loop ileostomy only 1
• Damage control should be started as soon as possible after resuscitation 1

SEMS (Self-Expanding Metal Stents):

• SEMS as bridge to elective surgery for right-sided obstructing colon cancer is NOT recommended 1
• May represent an option only in high-risk patients 1
• In palliative setting, SEMS can be an alternative to emergency surgery 1

Antibiotic Management:

• Prophylactic antibiotics targeting Gram-negative bacilli and anaerobes are mandatory 1
• Discontinue after 24 hours (or 3 doses) if no systemic infection 1
• For perforation, therapeutic antibiotics are always required; in critically ill patients with sepsis, use broader-spectrum antimicrobials early 1

If Simple Constipation (No Complete Obstruction)

Once mechanical obstruction is ruled out:

• Add a stimulant laxative immediately—bisacodyl 10-15 mg orally 2-3 times daily with goal of one non-forced bowel movement every 1-2 days 2
• Continue existing osmotic laxative (polyethylene glycol) as combination therapy is more effective than monotherapy 2
• Discontinue constipating medications (opioids, anticholinergics, calcium channel blockers) if medically feasible 2
• Reassess in 24-48 hours after initiating treatment 2
• If no response after 2-4 days, reassess for obstruction and consider more aggressive interventions 2

Pharmacologic Options for Chronic Constipation (After Obstruction Excluded)

• Linaclotide 290 mcg once daily is FDA-approved for chronic idiopathic constipation and IBS-C in adults 3
• Lubiprostone 24 mcg twice daily is FDA-approved for chronic idiopathic constipation in adults 4
• These newer agents represent significant advances in treating chronic constipation 5

Conservative Adjunctive Therapies

• Abdominal massage can stimulate peristalsis, decrease colonic transit time, and increase bowel movement frequency 6, 7
• Biofeedback therapy is preferred for dyssynergic defecation but is not widely available 8
• Rectal irrigation, transanal electrostimulation, and psychotherapy may be beneficial in selected cases 9

Key Clinical Pitfalls

• Never confuse right-sided constipation with right-sided obstruction—the former requires laxatives, the latter requires surgical intervention 2
• Colorectal cancer accounts for approximately 60% of large bowel obstructions, making imaging essential before treatment 10
• Colonic pseudo-obstruction can mimic mechanical obstruction but typically does not require surgical intervention 10
• Surgical treatment of chronic constipation is performed only in exceptional cases; a "too long gut" (dolichocolon) per se is never an indication for surgery 5