Last reviewed: March 2026
Contents
MDM Templates
Functional Constipation
Patient presents with abdominal discomfort and decreased bowel movements. Well appearing without distension, guarding, or peritoneal signs. History and exam not consistent with bowel obstruction, volvulus, appendicitis, or other surgical abdomen.
No red flags for malignancy — no unintentional weight loss, no iron deficiency anemia, no change in stool caliber, no family history of colon cancer.
Plan: Bowel regimen initiated — polyethylene glycol 17 g daily, senna 2 tablets daily, docusate 100 mg daily. High-fiber diet and increased fluid intake counseled.
Disposition: Discharge with return precautions for worsening abdominal pain, vomiting, bloody stool, inability to pass flatus, or fever. Follow up with PCP within 1 week. Patient understands that an early presentation of a more serious condition such as appendicitis or SBO is possible and that a recheck may be needed.
Fecal Impaction
Patient presents with constipation and rectal exam reveals hard stool in the rectal vault consistent with fecal impaction. No signs of obstruction on exam — abdomen is soft, passing flatus.
Manual disimpaction performed. Patient subsequently had bowel movement in the ED with symptomatic relief.
Plan: Aggressive bowel regimen — polyethylene glycol 17 g BID for 3 days then daily, senna, docusate. Counsel regarding fiber intake, hydration, and medication review for constipating agents.
Disposition: Discharge with PCP follow-up within 1 week for bowel regimen optimization. Return for recurrence, abdominal distension, or vomiting.
Obstipation / Concern for Obstruction
Patient presents with abdominal pain, distension, and inability to pass stool or flatus. Exam reveals distended abdomen with concern for obstruction versus severe constipation.
Imaging obtained to differentiate constipation from mechanical obstruction. Imaging demonstrates significant stool burden without transition point or signs of mechanical obstruction.
Plan: Aggressive bowel regimen including tap water enema and oral polyethylene glycol. Reassess after bowel movement.
Disposition: If improved — discharge with aggressive bowel regimen and PCP follow-up. If no improvement, admit for observation, serial abdominal exams, and escalation of bowel regimen.
Clinical Education
Red Flags
Constipation is usually benign, but it can mask dangerous diagnoses. Think about these before attributing the pain to constipation alone:[1]
| Red Flag | Consider |
| Acute onset, inability to pass flatus | Bowel obstruction, volvulus |
| New onset in elderly, weight loss | Colorectal malignancy |
| Saddle anesthesia, urinary retention | Cauda equina syndrome |
| Peritoneal signs, fever | Perforation, diverticulitis, appendicitis |
| Bloody stool, iron deficiency anemia | GI malignancy, IBD |
| Progressive distension, high-pitched bowel sounds | Large bowel obstruction, Ogilvie syndrome |
“Constipation” is a common ED misdiagnosis. Stool on an X-ray does not prove that constipation is causing the patient’s pain. Everyone has stool in their colon. Consider whether the constipation is the diagnosis or a coincidental finding in a patient with something else going on.[2]
Treatment Ladder
| Class | Agent | Dose | Notes |
| Osmotic | Polyethylene glycol (MiraLAX) | 17 g daily | First-line. Safe for daily use. |
| Osmotic | Lactulose | 30 mL daily–BID | Alternative osmotic. Causes more bloating. |
| Osmotic | Magnesium citrate | 240 mL PO | Avoid in renal failure. Rapid effect. |
| Stimulant | Senna | 2 tabs daily | Good add-on to osmotic agent. |
| Softener | Docusate (Colace) | 100 mg daily | Mild effect. Better for prevention. |
| Rectal | Fleet enema (sodium phosphate) | 118 mL PR | Avoid in renal failure, elderly, IBD. Max 2 doses 1 hr apart. |
| Rectal | Tap water enema | 500–1000 mL PR | Safer alternative to Fleet in at-risk patients. |
Opioid-Induced Constipation
Opioid-induced constipation (OIC) doesn’t respond well to standard laxatives alone. Opioids slow gut motility via mu receptors in the enteric nervous system. Standard bowel regimens help but may be insufficient. Peripherally acting mu-opioid receptor antagonists (PAMORAs) — methylnaltrexone (SQ), naloxegol (PO) — target gut opioid receptors without reversing central analgesia.[3]
In the ED, use the standard bowel regimen (PEG + senna + docusate), ensure the patient has a bowel movement before discharge if possible, and recommend PCP follow-up for PAMORA prescription if refractory. Always review the opioid regimen and advocate for dose reduction or rotation if feasible.
Pediatric Constipation
Functional constipation is extremely common in children — peak incidence at toilet training age (2–4 years). The Rome IV criteria define it in children, but in the ED, the diagnosis is clinical: infrequent hard stools, painful defecation, and often stool withholding behavior.[4]
PEG (MiraLAX) is first-line in pediatrics. Dose: 0.5–1 g/kg/day (max 17 g). For disimpaction: 1–1.5 g/kg/day for 3 days. Enemas are reserved for severe impaction — Fleet enemas should be avoided in children under 2 due to electrolyte risk.
Red flags in pediatric constipation: Failure to pass meconium in first 48 hours (Hirschsprung disease), bilious vomiting (obstruction), abdominal distension in a neonate, growth failure, or empty rectal vault with significant distension (raises concern for Hirschsprung disease — these patients don’t retain stool in the rectum).[5]
Disposition
Admit if: Concern for bowel obstruction, volvulus, fecal impaction not responsive to ED management, significant electrolyte abnormalities from enemas, or inability to tolerate PO.
Discharge if: Functional constipation with reassuring exam, improved symptoms after bowel regimen, tolerating PO, reliable follow-up. Counsel on maintenance bowel regimen — most patients benefit from daily PEG for at least 2–4 weeks, not just PRN use.
References
- Lembo A, Camilleri M. Chronic constipation. N Engl J Med. 2003;349(14):1360-1368. PubMed
- Freedman SB et al. Diagnosing clinically significant constipation with abdominal radiographs. J Pediatr. 2021;232:130-136. PubMed
- Argoff CE et al. Consensus recommendations on initiating prescription therapies for opioid-induced constipation. Pain Med. 2015;16(12):2324-2337. PubMed
- Tabbers MM et al. Evaluation and treatment of functional constipation in infants and children: evidence-based recommendations from ESPGHAN and NASPGHAN. J Pediatr Gastroenterol Nutr. 2014;58(2):258-274. PubMed
- Heuckeroth RO. Hirschsprung disease — integrating basic science and clinical medicine to improve outcomes. Nat Rev Gastroenterol Hepatol. 2018;15(3):152-167. PubMed
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