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Nursing Field Notes / Gastrointestinal · Med-Surg Course

Colonoscopy 🔎

The prep · during · the complication you watch for

NG-398 Gastrointestinal ADHD-friendly visual edition

Most of the exam questions about colonoscopy are about the preparation and the hours afterwards, not the procedure itself. The one complication that matters is perforation.

Screening startsAge 45, then every 10 years if normal
Clear liquidsNothing red or purple — it looks like blood
The complicationPerforation — pain, rigidity, fever, bleeding
AfterLeft side, expect cramping and flatus. That is normal.

🧨 What starts it

The preparation and recovery on a timeline from three days before to the hours afterwards, with the clear-liquid rule, why nothing red or purple is allowed, and the perforation to watch for.
Almost every question here is about the prep and the hours afterwards rather than the procedure itself. Swipe it sideways if it is cut off, or tap to open it full size.
Why it is done
  • Screening for colorectal cancer, and the only test that both finds and removes polyps in one visit.
  • Investigating rectal bleeding, iron-deficiency anemia, a change in bowel habit, unexplained weight loss.
  • Monitoring inflammatory bowel disease and surveillance after polyps or cancer.
  • The scope goes from the rectum to the caecum, so it sees the whole large bowel — a sigmoidoscopy only sees the last part.
Who gets screened, and when
  • Average risk: start at 45, repeat every 10 years if normal.
  • Family history of colorectal cancer in a first-degree relative: start at 40, or 10 years before their diagnosis age.
  • Inflammatory bowel disease: 8 years after diagnosis, then every 1 to 2 years.
  • Polyps found: repeat sooner, based on number and type.
What stops it going ahead

Active diverticulitis, suspected perforation, toxic megacolon, or an unstable patient. And an inadequate prep — a colon you cannot see is a colonoscopy worth repeating.

🔎 What you will see

Preparation — where the questions are
  • Clear liquid diet for 1 to 3 days beforehand.
  • Nothing red, purple or blue — the dye looks like blood on the screen. Broth, apple juice, plain tea, clear sports drinks are fine.
  • Bowel prep (polyethylene glycol) the evening before. She must finish it. Chilling it and using a straw helps.
  • NPO after midnight, or as the unit directs.
  • Hold anticoagulants and antiplatelets as prescribed — polyps may be removed.
  • Diabetes: the insulin and oral agents need adjusting for a day of clear liquids. Ask.
  • Signed consent before any sedation is given.
  • She needs a ride home. Sedation means she cannot drive.
During
  • Left lateral (Sims) position, knees drawn up.
  • Moderate sedation — midazolam plus an opioid, or propofol.
  • Monitor oxygen saturation, blood pressure and level of consciousness continuously. Over-sedation is the immediate risk.
  • Air is insufflated to open the bowel, which is why she cramps afterwards.
What is normal afterwards

Cramping, bloating and passing a lot of flatus. That is the air coming out and it is expected. A small amount of spotting after a biopsy is also expected.

🩺 What you do

After the procedure
  • Vital signs per protocol until she is fully awake.
  • Nothing by mouth until the gag reflex returns if the throat was sprayed — that applies to an EGD; for colonoscopy alone it is sedation recovery that governs.
  • Encourage ambulation and passing flatus — it relieves the cramping.
  • Resume the usual diet once alert, starting light.
  • Sedation teaching: no driving, no legal documents, no alcohol for 24 hours.
  • Tell her results and biopsy timing before she leaves.
What she reports to you at home
  • Severe or increasing abdominal pain
  • A firm, distended abdomen
  • Fever
  • Heavy rectal bleeding — more than spotting, or passing clots
  • Dizziness or fainting

Any of these means going back in, not waiting until morning.

Perforation — the one to recognize

The bowel wall is torn by the scope or during polyp removal. It presents as severe abdominal pain, a rigid distended abdomen, fever and rectal bleeding, usually within hours.

  • Stop oral intake, keep her flat with knees bent, take vital signs.
  • Notify the provider immediately — this becomes peritonitis and surgery.
  • Do not give anything by mouth and do not give a laxative or enema.

⚡ Quick recall

Screening startsAge 45, then every 10 years if normal
Clear liquidsNothing red or purple — it looks like blood
The complicationPerforation — pain, rigidity, fever, bleeding
AfterLeft side, expect cramping and flatus. That is normal.
At what age does average-risk colorectal screening start, and how often?
Age 45, then every 10 years if it is normal.
Which clear liquids are not allowed?
Anything red, purple or blue — the color is mistaken for blood.
She is cramping and passing a lot of gas afterwards. Is that a problem?
No, that is expected. It is the insufflated air leaving.
Which post-procedure findings mean perforation?
Severe pain, a rigid distended abdomen, fever and rectal bleeding.
What must be arranged before she is sedated?
Signed consent, and a ride home. She cannot drive for 24 hours.