Evaluation and Management of Constipation

Initial Assessment

The American Gastroenterological Association recommends performing a thorough digital rectal examination to rule out fecal impaction, which is the most urgent concern after 10 days without defecation, in patients with constipation 1, 2, 3.
Assess for hard stool in the rectal vault, which indicates impaction requiring immediate disimpaction, in patients presenting with constipation 1, 2.
Evaluate pelvic floor motion during simulated evacuation to detect dyssynergic defecation, a condition characterized by impaired coordination of the pelvic floor muscles during defecation, in patients with constipation 3.
Check for perianal soiling, anal tone, and puborectalis muscle function, which are important indicators of anorectal function, in patients with constipation 3.

Perform abdominal examination and obtain an abdominal X-ray to rule out mechanical bowel obstruction, especially if the patient has abdominal distension, severe pain, or systemic toxicity, in patients with constipation 1, 2.
The American Gastroenterological Association recommends obtaining only a complete blood count (CBC) as the sole routine test, as the diagnostic yield of other tests is low, in patients with constipation 3.
Order metabolic tests, such as thyroid-stimulating hormone, calcium, and glucose, only if specific symptoms suggest secondary causes, such as unexplained weight changes or muscle weakness, in patients with constipation 3.

The American Gastroenterological Association recommends colonoscopy for patients with alarm features, such as age >50 years without prior colorectal cancer screening, acute onset of constipation, rectal bleeding, or unexplained anemia, in patients with constipation 3.
Do not perform colonoscopy in patients without alarm features, even with chronic constipation, as the risk of colorectal cancer is low, in patients with constipation 3.

Administer glycerin suppository and/or mineral oil retention enema, and perform manual disimpaction with pre-medication, if needed, for patients with confirmed fecal impaction, as initial management 1, 2.
Start bisacodyl 10-15 mg daily plus polyethylene glycol (MiraLAX) 17g in 8 oz water twice daily, with goal of one non-forced bowel movement every 1-2 days, for patients with severe constipation, as initial management 1, 2, 6.
Ensure adequate hydration, at least 64 oz daily, as polyethylene glycol requires fluid to work effectively, in patients with constipation 6.