All EMS presentations
GIClinical presentation

Constipation / fecal impaction

A streamlined, differential-led presentation for rapid clinical review.

Clinical snapshot

Twenty-second review

  • Constipation and fecal impaction result from slow transit, dehydration, immobility, medication, outlet dysfunction, or obstruction and can cause pain, overflow diarrhea, or urinary retention.
  • Peritonism, persistent vomiting, marked distension, shock, GI bleeding, fever, or absent flatus after surgery raises concern for obstruction or perforation.
  • Keep urinary retention or overflow diarrhea in the differential; overlapping or concurrent illness remains possible.
  • For constipation / fecal impaction, trends and combinations of findings are more informative than one isolated vital sign.
Differentials

Compare the clinical patterns

The repeated material is grouped inside each possibility. Open only the condition you need.

Serious3 conditions
Bowel obstructionTime-sensitive high-risk possibility

HPI

Clarify last bowel movement and usual pattern; pain, distension or vomiting; passing flatus.

Signs & symptoms

Vomiting, distension, obstipation, severe pain, peritonism, or shock.

Focused exam

Inspect for distension, scars, hernia, emesis, or blood; auscultate and palpate gently for focal tenderness, guarding, or rigidity; Assess hydration, perfusion, and relevant chest, flank, pelvic, or rectal-history clues.

Brief pathophysiology

Bowel obstruction may cause constipation / fecal impaction through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

Serious abdominal disease may initially have normal vitals. Tachycardia, tachypnea, fever or hypothermia, and falling pressure support systemic compromise but are not required.

Heart rate (bpm)

May rise

Pain, dehydration, inflammation, or shock can cause tachycardia.

Blood pressure (mmHg)

May fall

Hypotension suggests dehydration, hemorrhage, sepsis, or late disease.

Respiratory rate (breaths/min)

May rise

Tachypnea may reflect pain, acidosis, sepsis, or diaphragmatic irritation.

Temperature (°C)

High, normal, or low

Fever supports infection; normal temperature does not exclude a surgical abdomen.

Front-load in the triage report

  • Bowel obstruction: Vomiting, distension, obstipation, severe pain, peritonism, or shock.
  • Last bowel movement and usual pattern?
  • Pain, distension or vomiting?
VolvulusTime-sensitive high-risk possibility

HPI

Clarify pain, distension or vomiting; passing flatus; medication contributors.

Signs & symptoms

Vomiting, distension, obstipation, severe pain, peritonism, or shock.

Focused exam

Assess hydration, perfusion, and relevant chest, flank, pelvic, or rectal-history clues; Assess hydration, abdomen, bowel sounds, distension, focal tenderness, hernia, medication use, mobility, and urinary symptoms.

Brief pathophysiology

Volvulus may cause constipation / fecal impaction through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

Gastrointestinal differentials may remain physiologically quiet early. Rate, pressure, respiratory response, and temperature help expose dehydration, bleeding, inflammation, or sepsis.

Heart rate (bpm)

May rise

Pain, dehydration, bleeding, or systemic illness can increase rate.

Blood pressure (mmHg)

May fall

Falling pressure suggests volume loss or systemic compromise.

Respiratory rate (breaths/min)

May rise

Pain, acidosis, sepsis, or diaphragmatic irritation can increase rate.

Temperature (°C)

Variable

Fever supports infection or inflammation but may be absent.

Front-load in the triage report

  • Volvulus: Vomiting, distension, obstipation, severe pain, peritonism, or shock.
  • Pain, distension or vomiting?
  • Passing flatus?
PerforationTime-sensitive high-risk possibility

HPI

Clarify passing flatus; medication contributors; prior surgery or obstruction.

Signs & symptoms

Vomiting, distension, obstipation, severe pain, peritonism, or shock.

Focused exam

Assess hydration, perfusion, and relevant chest, flank, pelvic, or rectal-history clues; Assess hydration, abdomen, bowel sounds, distension, focal tenderness, hernia, medication use, mobility, and urinary symptoms.

Brief pathophysiology

Perforation may cause constipation / fecal impaction through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

Serious abdominal disease may initially have normal vitals. Tachycardia, tachypnea, fever or hypothermia, and falling pressure support systemic compromise but are not required.

Heart rate (bpm)

May rise

Pain, dehydration, inflammation, or shock can cause tachycardia.

Blood pressure (mmHg)

May fall

Hypotension suggests dehydration, hemorrhage, sepsis, or late disease.

Respiratory rate (breaths/min)

May rise

Tachypnea may reflect pain, acidosis, sepsis, or diaphragmatic irritation.

Temperature (°C)

High, normal, or low

Fever supports infection; normal temperature does not exclude a surgical abdomen.

Front-load in the triage report

  • Perforation: Vomiting, distension, obstipation, severe pain, peritonism, or shock.
  • Passing flatus?
  • Medication contributors?
Common2 conditions
Functional constipationCommon presentation pattern

HPI

Clarify last bowel movement and usual pattern; pain, distension or vomiting; passing flatus.

Signs & symptoms

Infrequent hard stool, opioid use, dehydration, and gradual discomfort may fit.

Focused exam

Inspect for distension, scars, hernia, emesis, or blood; auscultate and palpate gently for focal tenderness, guarding, or rigidity; Assess hydration, perfusion, and relevant chest, flank, pelvic, or rectal-history clues.

Brief pathophysiology

Functional constipation may explain the presenting symptoms through a common clinical mechanism, while serial assessment checks for complications or an alternate cause.

Vital-sign pattern

What the trend may show

Possible pattern

Gastrointestinal differentials may remain physiologically quiet early. Rate, pressure, respiratory response, and temperature help expose dehydration, bleeding, inflammation, or sepsis.

Heart rate (bpm)

May rise

Pain, dehydration, bleeding, or systemic illness can increase rate.

Blood pressure (mmHg)

May fall

Falling pressure suggests volume loss or systemic compromise.

Respiratory rate (breaths/min)

May rise

Pain, acidosis, sepsis, or diaphragmatic irritation can increase rate.

Temperature (°C)

Variable

Fever supports infection or inflammation but may be absent.

Front-load in the triage report

  • Infrequent hard stool, opioid use, dehydration, and gradual discomfort may fit.
  • Last bowel movement and usual pattern?
  • Pain, distension or vomiting?
ImpactionCommon presentation pattern

HPI

Clarify pain, distension or vomiting; passing flatus; medication contributors.

Signs & symptoms

Infrequent hard stool, opioid use, dehydration, and gradual discomfort may fit.

Focused exam

Assess hydration, perfusion, and relevant chest, flank, pelvic, or rectal-history clues; Assess hydration, abdomen, bowel sounds, distension, focal tenderness, hernia, medication use, mobility, and urinary symptoms.

Brief pathophysiology

Impaction may explain the presenting symptoms through a common clinical mechanism, while serial assessment checks for complications or an alternate cause.

Vital-sign pattern

What the trend may show

Possible pattern

Gastrointestinal differentials may remain physiologically quiet early. Rate, pressure, respiratory response, and temperature help expose dehydration, bleeding, inflammation, or sepsis.

Heart rate (bpm)

May rise

Pain, dehydration, bleeding, or systemic illness can increase rate.

Blood pressure (mmHg)

May fall

Falling pressure suggests volume loss or systemic compromise.

Respiratory rate (breaths/min)

May rise

Pain, acidosis, sepsis, or diaphragmatic irritation can increase rate.

Temperature (°C)

Variable

Fever supports infection or inflammation but may be absent.

Front-load in the triage report

  • Infrequent hard stool, opioid use, dehydration, and gradual discomfort may fit.
  • Pain, distension or vomiting?
  • Passing flatus?
Mimics2 conditions
Urinary retentionImportant alternative presentation

HPI

Clarify last bowel movement and usual pattern; pain, distension or vomiting; passing flatus.

Signs & symptoms

Pelvic pressure and leakage can confuse the primary problem.

Focused exam

Inspect for distension, scars, hernia, emesis, or blood; auscultate and palpate gently for focal tenderness, guarding, or rigidity; Assess hydration, perfusion, and relevant chest, flank, pelvic, or rectal-history clues.

Brief pathophysiology

Urinary retention can resemble constipation / fecal impaction through overlapping symptoms or referred physiology despite a different primary mechanism.

Vital-sign pattern

What the trend may show

Possible pattern

Gastrointestinal differentials may remain physiologically quiet early. Rate, pressure, respiratory response, and temperature help expose dehydration, bleeding, inflammation, or sepsis.

Heart rate (bpm)

May rise

Pain, dehydration, bleeding, or systemic illness can increase rate.

Blood pressure (mmHg)

May fall

Falling pressure suggests volume loss or systemic compromise.

Respiratory rate (breaths/min)

May rise

Pain, acidosis, sepsis, or diaphragmatic irritation can increase rate.

Temperature (°C)

Variable

Fever supports infection or inflammation but may be absent.

Front-load in the triage report

  • Pelvic pressure and leakage can confuse the primary problem.
  • Last bowel movement and usual pattern?
  • Pain, distension or vomiting?
Overflow diarrheaImportant alternative presentation

HPI

Clarify pain, distension or vomiting; passing flatus; medication contributors.

Signs & symptoms

Pelvic pressure and leakage can confuse the primary problem.

Focused exam

Assess hydration, perfusion, and relevant chest, flank, pelvic, or rectal-history clues; Assess hydration, abdomen, bowel sounds, distension, focal tenderness, hernia, medication use, mobility, and urinary symptoms.

Brief pathophysiology

Overflow diarrhea can resemble constipation / fecal impaction through overlapping symptoms or referred physiology despite a different primary mechanism.

Vital-sign pattern

What the trend may show

Possible pattern

Volume loss may first appear as tachycardia or postural symptoms; hypotension is a later sign. Fever or blood loss changes the likely cause and risk.

Heart rate (bpm)

May rise

Tachycardia may reflect volume depletion, fever, or distress.

Blood pressure (mmHg)

May fall

Relative or orthostatic change can precede resting hypotension.

Pulse pressure (mmHg)

May narrow

Reduced stroke volume can narrow pulse pressure as depletion worsens.

Temperature (°C)

Variable

Fever supports infection; hypothermia may occur in severe illness.

Front-load in the triage report

  • Pelvic pressure and leakage can confuse the primary problem.
  • Pain, distension or vomiting?
  • Passing flatus?
Red flags

Findings that should escalate concern

  • Peritonism, persistent vomiting, marked distension, shock, GI bleeding, fever, or absent flatus after surgery raises concern for obstruction or perforation.
  • Bowel obstruction, volvulus, or perforation: Vomiting, distension, obstipation, severe pain, peritonism, or shock.
Related medications

Medication recognition

HydromorphoneOxycodoneMethadoneNaloxone
Related EMS presentations

Continue the clinical pathway

GIAbdominal painGeneral MedicalNausea / vomitingGIDiarrheaGU/RenalUrinary complaint / UTI / retentionPalliativePalliative / end-of-life symptom crisis
References

Clinical and academic sources

Curated clinical guidance and peer-reviewed evidence supporting this presentation. Current BCEHS guidance, medical direction, and local policy remain authoritative for practice.

BCEHS Handbook — specific CPGs

  1. E05: Abdominal PainBC Emergency Health Services Handbook

    Official BCEHS clinical practice guidance for abdominal pain.

Supporting clinical and academic evidence

  1. Appropriateness Criteria: Acute Nonlocalized Abdominal PainAmerican College of Radiology

    Evidence-based diagnostic context for acute nonlocalized abdominal pain.

  2. CEDIS Presenting Complaint List updateCanadian Association of Emergency Physicians

    Presenting-complaint terminology and categorization context. It does not establish a prehospital “top 100” ranking.

  3. Emergency department evaluation and management of constipationEmergency Medicine Practice · 2024

    Constipation, fecal impaction, obstruction and perforation red flags, and emergency assessment.