Name: Constipation — bulletproof documentation — ER Toolkit
Creator: Kim Trinh, MD

Constipation is a clinical diagnosis — and a diagnosis of exclusion. The defensible chart starts from the assumption that the absent bowel movement might be a symptom of something dangerous, documents the rectal exam, screens the cancer red flags, and recognizes that a "large stool burden" on x-ray does not explain abdominal pain.

01What's at stake

The job in the ED is to exclude the emergent mimics and the complications before prescribing a laxative. Obstruction, volvulus, Ogilvie syndrome, and cord compression masquerade as constipation; appendicitis or diverticulitis can cause an ileus that looks like it. And severe impaction can progress to stercoral colitis and perforation — which often presents with normal vital signs and no pain, only tenderness, especially in the frail elderly.

02Can't-miss diagnoses

Bowel obstruction / volvulus / Ogilvie — distension, vomiting, no flatus; a large-bowel or sigmoid volvulus is a surgical emergency.
Fecal impaction → stercoral colitis / perforation — pressure necrosis of the colon wall; subtle presentation, often normal vitals, tenderness on exam → CT. → CT if concern
Colorectal malignancy — the evidence-supported red flags are rectal bleeding, weight loss, and unexplained anemia (a change in bowel habit alone is weak); refer for colonoscopy.
Ileus from intra-abdominal disease — appendicitis, diverticulitis, pancreatitis, pyelonephritis.
Spinal cord compression — constipation/retention with neuro signs.

03History & exam

Red flags: fever, vomiting, severe/localized pain, distension, rectal bleeding, weight loss, unexplained anemia, new onset in an older adult.
Digital rectal exam — guideline-recommended for this complaint: sphincter tone, stool in the vault (impaction), masses, fissures, blood. → rectal exam
Medication review (opioids, anticholinergics, iron/calcium), comorbidities (diabetes, hypothyroidism, neurologic disease), and what home remedies failed.
Obstruction/complication screen — a plain film is insensitive and can mislead; use CT when obstruction or stercoral colitis is a concern. → don't be falsely reassured by a film

Skip the typing

Work the case in the Constipation Workup — it records the obstruction/red-flag screen and the rectal exam, and assembles an MDM that documents the dangerous mimics and complications were excluded before a benign label.

04Management

Disimpaction first for a hard fecaloma (manual ± enema) — oral laxatives alone are ineffective against an obstructing impaction (watch for a vagal response).
Laxative ladder: osmotic first-line (PEG; lactulose; magnesium — avoid in renal impairment), then stimulant (bisacodyl/senna). Docusate is no better than placebo; fiber is for prevention, not the acute episode.
Enemas as adjuncts (avoid sodium phosphate enemas in young children, the very elderly, and renal impairment).
Opioid-induced constipation: combine osmotic + stimulant; PAMORAs for refractory cases (refer); co-prescribe a bowel regimen with opioids.
Disposition: discharge most with a tailored regimen and PCP/GI referral; admit the emergent mimic or diagnosed stercoral colitis.

05What to document

▼ weak

"Constipated. X-ray shows lots of stool. Gave a laxative, discharged."

▲ defensible

"No BM ×4 days. No vomiting, no distension, soft non-tender abdomen with flatus (no obstruction/volvulus/Ogilvie); no fever or focal tenderness (no ileus from appendicitis/diverticulitis). Rectal exam: normal tone, soft stool in the vault (no hard impaction), no mass, guaiac-negative (no bleeding). No weight loss or anemia — but new change in habit at 55 → colonoscopy referral. Started PEG + senna, bowel regimen counseled. Return precautions for severe/worsening pain, vomiting, distension, fever, bleeding, or no BM despite the regimen. (Concern for stercoral colitis would prompt CT, not reliance on the plain film.)"

06Where charts fail

Attributing abdominal pain to a "large stool burden" on x-ray (premature closure) and missing an ileus/obstruction.
Skipping the rectal exam — missing impaction and the stercoral-colitis pathway.
Missing stercoral colitis in the frail elderly (normal vitals, no pain, but tenderness).
Not screening/referring for the cancer red flags (bleeding, weight loss, anemia).
Magnesium in renal impairment; sodium phosphate enemas in the high-risk; docusate as monotherapy.

07Sources

Richardson C. Emergency department evaluation and management of constipation. Emergency Medicine Practice (EB Medicine). 2024;26(3).
Chang L, Chey WD, Imdad A, et al. AGA-ACG clinical practice guideline: pharmacological management of chronic idiopathic constipation. Am J Gastroenterol. 2023;118(6):936-954.
Keim AA, Campbell RL, Mullan AF, et al. Stercoral colitis in the emergency department. Ann Emerg Med. 2023;82(1):37-46.
Adelstein BA, Macaskill P, Chan SF, et al. Most bowel cancer symptoms do not indicate colorectal cancer: a systematic review. BMC Gastroenterol. 2011;11:65.

Constipation: documentation that holds up