What is the recommended next step for a 46-year-old male with chronic rectal pain and pressure, worsening with prolonged sitting, and normal colonoscopy and digital rectal exam results?

From the Guidelines

I would recommend anorectal manometry for this 46-year-old gentleman. This diagnostic test would be most appropriate given his symptoms of dull rectal ache and pressure that worsens with sitting and improves with standing, which are consistent with levator ani syndrome or pelvic floor dysfunction. Anorectal manometry can evaluate pelvic floor muscle function, assess for paradoxical contraction of the puborectalis muscle during defecation, and measure anal sphincter pressures. The patient's normal colonoscopy rules out inflammatory or neoplastic causes, while his digital rectal exam showing tenderness with palpation and traction suggests pelvic floor muscle dysfunction, as supported by the American Gastroenterological Association's position on constipation 1.

The chronicity of symptoms (5 months), normal stool consistency, absence of hemorrhoids, and presence of anxiety (which can contribute to pelvic floor disorders) further support this approach. According to the most recent guidelines on evaluating anorectal disorders, anorectal physiology testing, including anorectal manometry, is recommended for patients with suspected pelvic floor disorders based on history or examination findings 1. Anorectal manometry results would guide appropriate treatment, which might include pelvic floor physical therapy, biofeedback, muscle relaxants, or other targeted interventions based on specific findings of muscle dysfunction.

Key points to consider in this patient's evaluation include:

• The importance of a thorough digital rectal examination, as emphasized by 1, which has already been performed and indicates pelvic floor muscle dysfunction.
• The role of anorectal manometry in diagnosing and managing pelvic floor disorders, as highlighted in 1.
• The potential for anxiety to contribute to pelvic floor disorders, suggesting a holistic approach to treatment that may include addressing the patient's anxiety.
• The need to rule out other causes of rectal pain and pressure, such as inflammatory or neoplastic conditions, which has been done through the patient's normal colonoscopy.

From the Research

Diagnosis and Testing

The patient presents with symptoms of dull ache and pressure in the rectum, which worsens with prolonged sitting and improves with standing. The patient's medical history is positive for anxiety, and the digital rectal exam reveals increased tenderness on palpation. Given the patient's symptoms and exam findings, the following diagnostic tests are considered:

• Anorectal manometry (ARM) is a diagnostic test that measures intraluminal anal and rectal pressures, providing an objective evaluation of anorectal functional parameters 2.
• The rectal balloon expulsion test is a useful, low-cost, radiation-free, outpatient assessment tool for impaired evacuation that is performed and interpreted in conjunction with ARM 3.

Recommendations

Based on the patient's symptoms and exam findings, the following recommendations are made:

• Anorectal manometry (ARM) is recommended to assess anorectal sensorimotor functions and guide management in patients with defecatory disorders, fecal incontinence, constipation, and other anorectal disorders 2, 4, 3.
• The rectal balloon expulsion test may be considered as an additional diagnostic tool to assess impaired evacuation 4, 3.
• Balloon testing or explosion is not a recommended diagnostic test for this patient's symptoms.

Rationale

The rationale for recommending ARM is based on its ability to provide detailed information on anorectal and pelvic floor muscle function and synergy, which can help guide treatment and management of anorectal disorders 2, 4, 3. The rectal balloon expulsion test is a useful adjunct to ARM, providing additional information on impaired evacuation 4, 3.

Key Points

• Anorectal manometry (ARM) is a useful diagnostic test for assessing anorectal sensorimotor functions and guiding management in patients with defecatory disorders, fecal incontinence, constipation, and other anorectal disorders 2, 4, 3.
• The rectal balloon expulsion test is a useful, low-cost, radiation-free, outpatient assessment tool for impaired evacuation that is performed and interpreted in conjunction with ARM 3.
• ARM and the rectal balloon expulsion test should be interpreted with reference to age- and sex-matched normal values, clinical features, and results of other tests 3.