One-liner#

Evaluate constipation to identify secondary causes (medications, metabolic, structural) and alarm features requiring workup, then manage with a stepwise laxative approach while addressing lifestyle factors.

Quick nav#

• Red flags / send to ED
• Key history
• Focused exam
• Differential (quick pattern recognition)
• Workup
• Initial management
• Management by diagnosis
• Follow-up
• Patient instructions
• Smartphrase snippets

Red flags / send to ED#

• Signs of bowel obstruction: vomiting, severe distension, obstipation, severe pain
• Fecal impaction with overflow incontinence and hemodynamic instability
• Severe abdominal pain with peritoneal signs
• Suspected volvulus (severe pain, distension, elderly)

Alarm features (warrant expedited workup)#

• New-onset constipation in patient >50 without clear cause
• Unintentional weight loss
• Rectal bleeding or hematochezia
• Iron deficiency anemia
• Family history of colorectal cancer or IBD
• Narrowing of stool caliber (“pencil-thin stools”)
• Severe or worsening symptoms despite treatment
• Palpable abdominal or rectal mass

Key history#

Define constipation (Rome IV criteria for functional constipation): Must include ≥2 of the following for ≥3 months (onset ≥6 months ago):

• Straining >25% of defecations
• Lumpy or hard stools >25% of defecations
• Sensation of incomplete evacuation >25% of defecations
• Sensation of anorectal obstruction/blockage >25% of defecations
• Manual maneuvers to facilitate >25% of defecations
• <3 spontaneous bowel movements per week

Stool characteristics:

• Frequency: what is “normal” for this patient?
• Consistency: use Bristol Stool Scale (Type 1–2 = constipation)
• Straining: suggests outlet dysfunction or hard stool
• Incomplete evacuation: suggests pelvic floor dysfunction
• Need for manual disimpaction: suggests pelvic floor dysfunction

Timeline:

• Lifelong vs recent onset (recent onset more concerning for secondary cause)
• Gradual vs sudden (sudden suggests obstruction, medication, or acute illness)
• Constant vs intermittent

Associated symptoms:

• Abdominal pain: relieved with defecation (IBS-C) vs constant (obstruction, mass)
• Bloating: common with constipation
• Nausea/vomiting: suggests obstruction
• Rectal bleeding: hemorrhoids, fissure, or concerning for malignancy
• Fecal incontinence: overflow from impaction

Medication review (critical—most common cause):

Dietary and lifestyle:

• Fiber intake (goal 25–30 g/day)
• Fluid intake
• Physical activity level
• Ignoring urge to defecate (common contributor)
• Bathroom access/privacy issues

Medical history:

• Diabetes (autonomic neuropathy)
• Hypothyroidism
• Parkinson’s disease
• Multiple sclerosis
• Spinal cord injury
• Depression
• Prior abdominal/pelvic surgery

Focused exam#

• Vitals: usually normal
• Abdominal: distension, tenderness, palpable stool (LLQ), masses, surgical scars, bowel sounds
• Rectal exam (essential):
  • Inspect: hemorrhoids, fissures, skin tags, prolapse
  • Tone: decreased (neurologic) or increased (anismus)
  • Stool in vault: hard stool, impaction
  • Masses: rectal cancer
  • Squeeze and push: assess pelvic floor function
  • Occult blood testing
• Neurologic: if neurologic cause suspected (Parkinson’s, MS, spinal cord)
• Thyroid: goiter (hypothyroidism)

Differential (quick pattern recognition)#

Common/likely (outpatient)#

Can’t-miss / urgent#

Workup#

Most patients need minimal workup—history and exam are usually sufficient.

Initial workup (if not clearly functional):

• TSH: hypothyroidism
• Calcium: hypercalcemia
• CBC: anemia (bleeding, malignancy)
• BMP: electrolytes, renal function

When to scope:

• Age ≥45 and not up to date on CRC screening
• Alarm features (bleeding, weight loss, anemia, family history)
• New-onset constipation in older adult without clear cause
• Refractory to treatment

Specialized testing (GI referral):

• Anorectal manometry: suspected pelvic floor dysfunction
• Balloon expulsion test: dyssynergia
• Colonic transit study (Sitz markers): slow transit constipation
• Defecography: structural abnormalities, pelvic floor dysfunction

When NOT to do extensive workup:

• Lifelong constipation without alarm features
• Clear medication-induced with temporal relationship
• Responds to fiber and lifestyle changes
• Young patient meeting Rome IV criteria for functional constipation

Initial management#

Step 1: Address reversible causes

• Review and adjust medications if possible
• Increase fiber (25–30 g/day) gradually
• Increase fluid intake (8 glasses/day)
• Encourage physical activity
• Establish regular toilet time (after meals, when gastrocolic reflex strongest)

Step 2: Stepwise laxative approach

Management by diagnosis#

Functional/chronic idiopathic constipation#

Education:

• Common condition; not dangerous
• Lifestyle changes are foundation of treatment
• May need ongoing laxative use—this is safe
• Goal is comfortable, regular bowel movements (not necessarily daily)

Treatment:

Lifestyle (first-line):

• Fiber: 25–30 g/day (increase gradually to avoid bloating)
• Fluids: 8 glasses/day
• Exercise: regular physical activity
• Toilet habits: respond to urge; don’t delay; post-meal timing

Bulk-forming agents:

Osmotic laxatives:

Stimulant laxatives:

Note on docusate (Colace): Docusate alone is NOT effective for constipation—evidence shows it’s no better than placebo. Use only in combination with stimulant (senna-docusate) for stool softening in OIC.

Secretory agents (if above fail):

Follow-up: 4–6 weeks; adjust regimen based on response.

IBS-C (Constipation-predominant IBS)#

Education:

• IBS involves gut-brain interaction; not “just constipation”
• Abdominal pain is a key feature (distinguishes from functional constipation)
• Dietary changes, stress management, and medications all help

Treatment:

• Low-FODMAP diet may help
• Fiber (soluble preferred—psyllium)
• Osmotic laxatives (PEG)
• Linaclotide or plecanatide (FDA-approved for IBS-C; help pain + constipation)
• Lubiprostone (FDA-approved for IBS-C in women)
• Low-dose TCA (amitriptyline) if pain prominent—but may worsen constipation

Follow-up: 4–6 weeks; GI referral if refractory.

Opioid-induced constipation (OIC)#

Education:

• Opioids slow gut motility; tolerance does NOT develop to constipation
• Prevention is key—start laxatives when starting opioids
• May need specific medications that block opioid effect on gut

Treatment:

Prevention (start with opioid):

• Senna 8.6 mg + docusate 100 mg BID (Senokot-S)
• PEG 17 g daily
• Adequate fluids

If standard laxatives fail—PAMORAs (peripherally acting mu-opioid receptor antagonists):

Follow-up: 1–2 weeks after starting PAMORA; continue standard laxatives as adjunct.

Pelvic floor dysfunction (dyssynergic defecation)#

Education:

• Muscles that should relax during defecation are contracting instead
• Not a structural problem—it’s a coordination problem
• Biofeedback therapy is highly effective (70–80% success)

Treatment:

• Biofeedback therapy (first-line): teaches proper coordination; requires specialized therapist
• Avoid straining (worsens problem)
• Proper positioning: feet elevated (squatty potty), lean forward
• Fiber and osmotic laxatives as adjunct

Follow-up: GI referral for anorectal manometry and biofeedback therapy.

Fecal impaction#

Education:

• Hard stool mass that cannot be passed
• Common in elderly, immobile, opioid users
• Must be cleared, then prevent recurrence

Treatment:

Acute management:

1. Manual disimpaction if stool palpable in rectum
2. Enemas: mineral oil enema first (softens), then tap water or saline enema
3. Oral: high-dose PEG (e.g., GoLYTELY prep) if no obstruction
4. May require ED if severe or unable to clear

Prevention after clearance:

• Daily PEG or lactulose
• Scheduled stimulant laxative
• Address underlying cause (medications, immobility)
• Regular toileting schedule

Follow-up: Within 1 week to ensure resolution and establish prevention regimen.

Follow-up#

• Functional constipation: 4–6 weeks after starting treatment
• IBS-C: 4–6 weeks; GI referral if refractory
• OIC: 1–2 weeks after starting PAMORA
• Pelvic floor dysfunction: GI referral for biofeedback
• Fecal impaction: Within 1 week to confirm resolution

When to refer to GI:

• Alarm features requiring colonoscopy
• Refractory to stepwise laxative approach
• Suspected pelvic floor dysfunction
• Need for specialized testing (manometry, transit study)

Patient instructions#

• Eat more fiber-rich foods: fruits, vegetables, whole grains, beans. Aim for 25–30 grams per day.
• Drink plenty of water—at least 8 glasses per day.
• Exercise regularly; even walking helps keep your bowels moving.
• Don’t ignore the urge to have a bowel movement. Go when you feel the need.
• Try to have a regular time for bowel movements, such as after breakfast.
• Take your laxatives as prescribed. It’s safe to use them regularly if needed.
• Call the office if you have blood in your stool, severe pain, vomiting, or no bowel movement for more than a week despite treatment.

Smartphrase snippets#

.CONSTIPATIONFUNCTIONAL Chronic constipation without alarm features. Likely functional/primary constipation. Plan: increase fiber to 25–30 g/day, increase fluids, PEG 17 g daily. Discussed lifestyle modifications and stepwise laxative approach. Will reassess in 4–6 weeks.

.CONSTIPATIONNEWONSET New-onset constipation in [age >50/patient with alarm features]. Ordered [TSH, calcium, CBC, colonoscopy]. Will reassess after workup complete. Discussed importance of evaluation given [alarm feature].

.CONSTIPATIONOIC Opioid-induced constipation. Currently on [opioid]. Plan: senna-docusate BID + PEG daily. If inadequate response, will consider PAMORA (naloxegol or methylnaltrexone). Discussed that constipation is expected with opioids and requires ongoing management.

Related pages#

• Irritable Bowel Syndrome (problem) — comprehensive IBS management including IBS-C subtype
• Diarrhea (Chronic) (complaint) — IBS-D and mixed IBS evaluation
• Abdominal Pain (Chronic) (complaint) — functional abdominal pain syndromes
• Hypothyroidism (problem) — metabolic cause of constipation