Normal Elimination
Know the normal numbers so you can recognize what's not.
Urine
- Output: at least 30 mL/hr (about 1,500 mL/day). Report output < 30 mL/hr.
- Normal appearance: clear, pale yellow to amber, slightly aromatic.
- Dark/concentrated = dehydration; cloudy/foul = possible infection; red/pink = possible blood.
Stool
- Normal: brown, soft, formed; frequency varies (3/day to 3/week is normal).
- Black/tarry (melena) = upper GI bleed (or iron/bismuth); red = lower GI bleed; clay/pale = bile obstruction.
Adequate urine output (≥ 30 mL/hr) tells you the kidneys are perfused and working. Output below 30 mL/hr is one of the most commonly tested "report this" findings — but first check for a distended bladder or kinked catheter, because retention can mimic low production.
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Urinary Problems
Retention vs the four types of incontinence — match the pattern to the cause.
Urinary Retention
Inability to empty the bladder. Signs: bladder distension, discomfort, frequent small voids or no output. Common causes: BPH (enlarged prostate), post-op/anesthesia, and medications (anticholinergics, opioids). Assess with a bladder scan; an order for intermittent (straight) catheterization may be needed.
Types of Incontinence
- Stress
- Leaks with cough, sneeze, laugh, exertion (weak pelvic floor). Key intervention: Kegel (pelvic floor) exercises, weight management.
- Urge
- Sudden strong urge, can't hold it (overactive bladder). Key intervention: bladder training, scheduled voiding, anticholinergic meds.
- Overflow
- Constant dribbling — bladder never fully empties (obstruction, BPH). Key intervention: treat obstruction; intermittent catheterization.
- Functional
- Can't reach the toilet in time (mobility, cognition). Key intervention: scheduled toileting, bedside commode, easy clothing.
Stress = leaks when abdominal pressure rises (cough/sneeze) → strengthen the floor with Kegels. Urge = "gotta go RIGHT now" → bladder training and scheduled voiding. Telling these two apart is a classic exam question.
Catheters & CAUTI Prevention
Catheter-associated UTI is a major preventable harm — these rules are heavily tested.
Types of Catheters
- Indwelling (Foley): stays in with a balloon; continuous drainage.
- Straight (intermittent): in and out to drain once (e.g., retention).
- Suprapubic: surgically placed through the abdomen.
- External (condom) catheter: fits over the penis; lowest infection risk — preferred when possible.
CAUTI Prevention
- Sterile technique on insertion (indwelling).
- Keep the drainage bag below the level of the bladder at all times — prevents backflow.
- Keep the bag off the floor; maintain a closed drainage system.
- Secure the tubing; avoid kinks and dependent loops.
- Routine perineal care; ensure adequate fluid intake.
- Remove the catheter as soon as possible — duration is the biggest risk factor.
If the drainage bag rises above the bladder (for example, during transfers or repositioning), urine can flow back up the tubing and introduce bacteria → CAUTI. Always keep the bag below bladder level and never rest it on the floor. Clamp the tubing briefly during a transfer if needed, then re-hang it low.
Bowel Problems
Constipation, diarrhea, and impaction — and the trap of "paradoxical diarrhea."
- Constipation
- Hard, dry, infrequent stool; straining. Management: increase fiber, fluids, and activity; stool softeners/laxatives as ordered.
- Diarrhea
- Frequent, loose, watery stool. Management: replace fluids/electrolytes, protect perianal skin, identify cause (infection, meds).
- Fecal impaction
- Hard mass lodged in the rectum that can't be passed. Management: oil-retention enema; gentle digital removal with an order; prevent with fiber/fluids/activity.
A patient with no real bowel movement for days who suddenly leaks liquid stool may have a fecal impaction — watery stool seeps around the hard mass (paradoxical diarrhea). Don't just treat it as diarrhea; assess for impaction, especially in immobile, dehydrated, or opioid-treated patients.
The first-line, non-drug answer for constipation is almost always the same trio: more fiber, more fluids, and more activity. Add a scheduled toileting time (especially after breakfast, using the gastrocolic reflex) before reaching for laxatives.
Enemas & Suppositories
Position, depth, and flow control are the testable details.
Enemas
- Position: left Sims' (left side-lying) — follows the colon's curve for better flow and retention.
- Insertion depth: about 3–4 inches in an adult, angled toward the umbilicus.
- Instill slowly; if cramping occurs, lower the bag or slow the flow (don't just stop).
- Types: normal saline (safest), tap water (don't repeat — water toxicity risk), soap-suds (irritating), oil-retention (softens impaction), hypertonic/Fleet (small volume).
Suppositories
- Place against the rectal wall (not into stool) for absorption; have the patient retain it.
- Some are timed with the urge to defecate (stimulant suppositories).
For an adult enema, the answer to "what position?" is left Sims', and "how far?" is 3–4 inches toward the navel. If the patient cramps, the fix is to slow or lower the solution — keep it going gently rather than aborting.
? What position is used for an enema, and how far is the rectal tube inserted in an adult?
Ostomy Care
Colostomy vs ileostomy, and the stoma colors that mean trouble.
- Colostomyfrom colon
- Output thickens the farther along: liquid (ascending) → formed (sigmoid). Main risks vary by site.
- Ileostomyfrom ileum
- Liquid, enzyme-rich, near-constant output. Main risks: skin breakdown (enzymes) and dehydration / electrolyte loss.
Stoma & Pouch Care
- A healthy stoma is pink to red and moist. Report a pale, dusky, purple, or black stoma — it signals impaired blood supply.
- A new stoma is normally edematous at first and shrinks over weeks.
- Protect the skin with a barrier; cut the opening to fit snugly around the stoma.
- Empty the pouch when it's about one-third to one-half full (prevents leaks and weight pull).
A stoma should look like the inside of your cheek — pink/red and moist. If it turns dusky, purple, or black, blood flow to the stoma is compromised (ischemia/necrosis). Report it to the provider immediately. Some bleeding when cleaning is normal; a color change is not.
Bowel & Bladder Training
Restoring control with schedules and pelvic-floor work.
- Bladder training: scheduled/prompted voiding, gradually lengthening intervals; Kegel exercises for stress incontinence.
- Bowel training: a consistent toileting time daily, ideally after a meal to use the gastrocolic reflex; adequate fiber and fluids.
- Promote privacy, normal positioning (upright/sitting), and prompt response to the urge.
- Limit bladder irritants (caffeine) for urge symptoms.
Eating stimulates colon activity (the gastrocolic reflex), so the best time to schedule bowel training is about 30 minutes after a meal — usually breakfast. Pairing toileting with this natural reflex makes a bowel program far more successful.
Specimen Collection
The right technique for each specimen keeps results accurate.
- Routine urinalysis: fresh sample in a clean container.
- Clean-catch / midstream: clean the perineum/meatus, begin voiding, then catch the midstream portion — used for culture and sensitivity (C&S).
- From an indwelling catheter: withdraw a sterile specimen from the sampling port (after cleaning it) — never from the drainage bag.
- 24-hour urine: discard the first void to start the clock, then collect all urine for 24 hours (keep on ice/refrigerated). Missing one void invalidates the test.
- Stool: for ova & parasites, occult blood (guaiac), or C. difficile — follow specific handling instructions.
Urine sitting in a drainage bag is old and contaminated, so a culture from the bag is unreliable. For a catheter specimen, clean the sampling port and aspirate fresh urine from there. For a clean-catch, the midstream portion avoids skin contaminants.
? When collecting a urine specimen from an indwelling catheter, where do you aspirate from — and why not the bag?
Frequently Asked Questions
Common student questions on this topic.
What is the minimum normal urine output, and when should low output be reported?
What are the main types of urinary incontinence?
How do you prevent a catheter-associated UTI (CAUTI)?
What is fecal impaction and what is a classic sign?
What position is used for an enema, and how far is the tube inserted?
What is the difference between a colostomy and an ileostomy, and what stoma color is a problem?
Quick-Reference Cheatsheet
Every key point from this guide on a single printable page.
Elimination (Bowel & Bladder) Cheatsheet
One-page PDF — free download.