Constipation

on call  ›  complaints
reference sheet complaint/constipation

Constipation

at the bedside
  • check vitals + RBS
  • assess hydration + mental status
  • establish IV access if unstable
don’t miss
  • severe pain + vomiting + no flatus → obstruction
  • distension + absent bowel sounds → ileus
  • neurological deficit → spinal pathology
  • weight loss + new onset → malignancy
  • apparent diarrhea in prolonged constipation (especially elderly/immobile) → fecal impaction with overflow: antidiarrheals worsen it, DRE confirms → diarrhea

focused check
  • duration, last bowel motion, flatus; pain, distension; post-op status
  • medications: opioids, chemotherapy, diuretics, other constipating drugs
  • metabolic / endocrine: hypothyroidism, hypercalcemia, hypokalemia: consider if new, refractory, or unexplained
examination
  • abdomen (distension, tenderness); DRE (impaction, bleeding); bowel sounds: normal q5–10 s, absent → ileus, hyperactive → obstruction

treat
obstruction suspected
  • NPO; IV fluids; labs CBC, RFT, lactate; imaging AXR / CT; NGT if significant vomiting, marked distension, or high-grade obstruction (not routine)
  • call Surgery STAT; do not give laxatives or enemas if obstruction or perforation is suspected
no obstruction
  • mild: hydration + fiber + glycerin suppository
  • moderate (> 48 hr): Movicol 1–2 sachets BID ± enema
  • severe (> 72 hr / symptomatic): DRE → rule out impaction; impacted → manual disimpaction, then suppository ± enema
laxative options
  • lactulose 15–30 mL PO BD (bloating, flatulence, cramps)
  • senna 7.5–15 mg PO nocte (cramps)
  • bisacodyl 5–10 mg PO/PR
  • avoid phosphate enemas in elderly, renal impairment, or volume depletion (phosphate nephropathy risk)
  • opioid-induced → senna + osmotic laxative; reduce opioid if possible
symptom control
  • pain → hyoscine butylbromide (Buscopan) 20 mg PO/IV or paracetamol 1 g IV
escalation

evidence
sourcetype
Fecal impaction with overflow diarrhea, case literatureevidence review
Metabolic causes of constipation, standard referenceevidence review

Verify indication, dose, allergies, interactions, renal/hepatic function and local protocols before prescribing.

related diarrhea· nausea & vomiting· abdominal pain· GI bleed· fever
go deeper MOC+ Vol 4 · Acute GI & Hepatology covers this in the full reference. or the complete set.

free the on-call checklist covers the whole shift on one printable page.

studying for the IM exam? the IM Rapid Review covers this in the same format. see the sample chapter.

reviewed Jul 2026updated Sep 2026file complaint/constipation