Usually a/w polypectomy, rarely accompanying diagnostic scope
Typically 1-2%, but higher with larger polyps or pro-bleeding risk factors
Immediate bleeding:
a/w techniques not involving cautery
Usually recognised during procedure
Usually managed with repeat scope if not fixed at time
Delayed:
Typically 5-7 days, up to a month
Thought to occur when eschar sloughs off
Usually needs scope
Management
Resuscitate and correct coagulopathy
Usually scope again - don't need to prep, but if patient is stable, could do a rapid prep
Tattoo the bleeding site in case you need to operate later
Angiographic embolisation can be considered, as long as you won't need to resect bowel at the site in future
Persistent bleeding needs an operation - usually with intra-operative colonoscopy to localise, then colotomy and direct haemostasis, then closure. If a resection is going to be required in the future anyway, may be better off resecting.
Perforation
Aetiology
Mechanical trauma from pressure (rectosigmoid region typically)
Barotrauma from excessive insufflation (typically caecum)
Electrocautery injury during polypectomy
Excessive looping
Overzealous stricture dilation
Incidence
Perforations from diagnostic scope are typically large (barotrauma or mechanical), whereas electrocautery perforations more often cause small localised perforations
Risk factors: (patient factors/technical factors)
Age
Multiple comorbidities
Diverticulosis
Obstruction
Resection of polyps >1cm in right colon
Inexperience
Presentation
Can become clear right afterwards, or days later with increasing abdominal sepsis (typically perforations that were initially contained, or polypectomy with cautery)
Investigation
Some say start with AXR - free air and local peritonitis are diagnostic, however small-volume pneumoperitoneum can be normal after colonoscopy (Schein's)!
CT - highly consider PO or rectal contrast
Treatment
Large perforations - usually surgery
Consider - would the patient require surgery for the colon lesion anyway? Might as well just do it…
Smaller can be managed non-op
Pneumoperitoneum is not necessarily an absolute indication for surgery
Good prognostic factors for non-op:
Prepped colon
No peritonitis, tachycardia, or fever
Retroperitoneal contained perforation
Sustained perforation during therapeutic scope
Clip closure of small perforations has been reported - but ONLY if it is recognised at time of scope, you can't do a repeat scope on a patient after the perforation has occur red - risk blowing open a contained perforation and contaminating the abdomen
Peritoneal toilet and primary suture closure of the perforation is usually sufficient
Consider bypass/diversion/resection
In established infection, primary closure with covering loop ileostomy may be useful - note that diversion is less useful if the patient is not prepped, and there is faeces above the injury anyway. Ileostomy preferred to loop colostomy to avoid interfering with future potential conduit required to fix the problem.
Post-polypectomy syndrome
Electrocoagulation injury to bowel wall, causing transmural burn and focal peritonitis without frank perforation
Can see fever, leucocytosis, focal tenderness up to 5 days later
Just needs antibiotics - can sometimes be treated as outpatient
Infection
Very uncommon - contaminated instruments with BBV has been reported
Gas explosion
APC can cause this
Incomplete prep, meaning methane is present
Incompletely absorbable carbohydrate preps such as lactulose, mannitol, sorbitol
