What is the best management approach for a patient with constipation and increased rectal tone on digital rectal exam (DRE)?

From the Guidelines

The best management approach for a patient with constipation and increased rectal tone on digital rectal exam (DRE) is to initiate a regimen that addresses the pelvic floor dysfunction likely causing the symptoms, starting with a combination of stool softeners and osmotic laxatives, along with pelvic floor physical therapy and dietary modifications. The patient's symptoms of difficulty passing stools, abdominal bloating, and fatigue, combined with the increased rectal tone on DRE, suggest pelvic floor dyssynergia, a condition where the pelvic floor muscles contract rather than relax during attempted defecation 1.

Initial Management

The initial management should include:

• Discontinuing any medications that can cause constipation, if feasible 1
• A therapeutic trial of fiber supplementation and/or osmotic or stimulant laxatives before anorectal testing 1
• Pelvic floor physical therapy, consisting of 6-8 weekly sessions focused on biofeedback techniques and muscle relaxation exercises
• Dietary modifications, including increased fiber (25-30g daily) and adequate hydration (2-3 liters daily)

Medical Therapy

The medical therapy should include:

• Stool softeners such as docusate sodium (100 mg twice daily)
• Osmotic laxatives like polyethylene glycol (17 g daily in water)
• Patients should also be instructed to practice proper defecation positioning using a footstool to create a squatting position and to perform daily pelvic floor relaxation exercises
• Warm sitz baths for 10-15 minutes can help relax the anal sphincter

Further Evaluation

If conservative measures fail after 4-6 weeks, consider referral for anorectal manometry to confirm the diagnosis, and possibly botulinum toxin injections to the puborectalis muscle in refractory cases 1. The use of enemas, such as osmotic micro-enema or docusate sodium enema, may be considered in patients with a full rectum or faecal impaction, but should be used cautiously and with consideration of potential adverse events 1.

From the FDA Drug Label

USE • relieves occasional constipation (irregularity) • generally produces a bowel movement in 1 to 3 days The most appropriate next step is to consider the use of polyethylene glycol (PO) to relieve constipation, as it can produce a bowel movement in 1 to 3 days.

• The patient's symptoms of difficulty passing stools, abdominal bloating, and excessive fluctuance are consistent with constipation.
• The presence of increased rectal tone on DRE suggests that the patient may have a functional gastrointestinal disorder, and the use of polyethylene glycol (PO) may be beneficial in managing her symptoms 2.

From the Research

Patient Presentation and History

• A 66-year-old woman presents with difficulty passing stools, episodes of abdominal bloating, excessive fluctuance, and fatigue over 15 years.
• She denies nausea, vomiting, blood in stool, or unintentional weight loss.
• Serum TSH is 3.2, free thyroxine is 1.2, Hgb is 12.5.
• DRE shows increased rectal tone.

Diagnostic Considerations

• The patient's symptoms and physical examination findings suggest constipation with increased rectal tone.
• The patient's laboratory results are largely unremarkable, with a normal thyroid function test and mild anemia.

Management Approach

• The most appropriate next step in managing this patient's constipation is to consider fiber supplementation, as evidenced by a systematic review and meta-analysis of randomized controlled trials 3.
• The study found that fiber supplementation, particularly with psyllium and pectin, can improve stool frequency, consistency, and quality of life in adults with chronic constipation.
• A higher response to treatment was apparent in fiber groups compared to control groups, with optimal results seen with higher fiber doses (>10 g/d) and treatment durations of at least 4 weeks.

Potential Benefits and Risks

• Fiber supplementation may improve the patient's constipation symptoms, including stool frequency and consistency.
• However, fiber supplementation may also increase flatulence, as seen in the study 3.
• The patient's increased rectal tone on DRE may also be addressed through fiber supplementation, although further evaluation and management may be necessary to fully address this finding.