Colon and Small Bowel—Lower GI Bleeding (LGIB)

Colon and Small Bowel—Lower GI Bleeding (LGIB)

Concept

Broad DDx but three common pathologies need to be ruled out: diverticulosis, angiodysplasia, and cancer.

Likely to be self-limited in over 80% pts. AVM’s likely to rebleed, but less likely in diverticular disease unless young age. ~10% pts will come to surgery.

Way Question May be Asked?

“ 69 y/o female seen in the ED for dizziness after abruptly moving her bowels for a large amount of maroon colored stools. She is tachycardic to 110s, but her BP is stable. What do you want to do?” May be given a pt that is stable or unsta- ble and make that determination in your mind early includ- ing if/when you plan to transfuse the pt. The scenario is likely to be pretty basic as the examiners want to get at your man- agement algorithm and your indications for surgery.

How to Answer?

Have a DDx

Diverticulosis (painless bleeding) Angiodysplasia (painless bleeding) Cancer

Ischemia IBD Infectious

Anorectal pathology

Small bowel pathology (tumor, Meckel’s diverticulum) Don’t forget about brisk bleeding from UGI source

History

Age (<30, consider IBD or Meckel’s otherwise divertic- ulosis dx/AVM most common)

Previous surgery (especially AAA)

Medications/known coagulopathy (ASA, coumadin use)

Prior bleeding episodes Trauma

Radiation (ischemia) Pain with bleeding episode Amount of bleeding, color

Dizziness or other evidence of shock

Physical Exam (brief and targeted in pt. with shock)

Vital signs (r/o shock) Signs of liver disease

Examine abdomen (prior scars) Rectal exam

Necessary Parts of Early Algorithm

Placing NGT and getting bilious aspirate Anoscopy

Rigid sigmoidoscopy (r/o rectal source)

Assess stability of patient (never at fault for putting in ICU)

Diagnostic Tests

Full laboratory panel including PT/PTT Bleeding time if pt on aspirin

Tagged RBC Scan (detects bleeding > 0.5 cc/min) Angiography (detects bleeding > 2 cc/min and can be

SMA injected first, then IMA followed by celiac trunk if first two negative therapeutic)

Colonoscopy (useful after prep in those pts who don’t require urgent operation)

Surgical Treatment

(1) Know when to go to OR:

transfusion of > 4 U pRBC in 24 h LGIB that causes hypotension

LGIB refractory to maximal medical therapy

Continuous bleeding and can’t identify a source (2) After tagged RBC scan

(a) If +, proceed to OR if unstable, angiogram if stable

(b) If −, can still repeat within 24 hr and can prep for colonoscopy

(3) After angiogram

(a) If +, vasopressin 0.2 U/min to control bleeding, no embolization of colonic pathology!

(b) If −, prep for colonoscopy

SMA injected first, then IMA followed by celiac trunk if first two negative

(4) If can identify source

(a) On right side, resection + primary anastomosis (b) On left side, resection with colostomy and

mucous fistula/Hartmann’s pouch (5) If can’t identify source

(a) Subtotal colectomy with primary ileorectal anastomosis or ileostomy depending on pts sta- bility

(b) If see blood in mid-ileum or above, consider small bowel source prior to subtotal colectomy

Common Curveballs

Entire colon filled with blood on colonoscopy Will be blood in terminal ileum

Colonic infarction after attempt at angiographic embolization of diverticular bleed

Will have to operate on pt before RBC scan or angiogram

Being asked when it is appropriate to perform:

Tagged RBC scan Angiography

Colonoscopy

And the advantages/disadvantages of each Pt will become unstable pre-op or intra-op

Pt will need several transfusions (what is your limit for going to OR?)

Won’t be able to identify a source pre-op or intra-op Ureter/duodenal/liver injury while mobilizing right colon Splenic injury will mobilizing splenic flexure

Hard peripheral liver lesion identified at time of emergency operation

Pt will have had prior abdominal/colonic surgery Pt will have had recent MI or severe cardiac disease Pt will have UGI source (change scenario)

Pt will take aspirin/Plavix/coumadin

Pt will have bleeding from stoma after subtotal colectomy Pt will be Jehovah’s witness and won’t accept blood

transfusions

Strikeouts

Embolizing colonic lesion identified by arteriogram Not placing NGT (failing to consider UGI source) Not performing rigid sigmoidoscopy

Not ruling out/correcting coagulopathy (coumadin, ASA, liver disease)

Performing long operation in elderly/unstable pt Not performing subtotal colectomy when can’t identify

source

Sending unstable pt for bleeding scan

Not considering angiogram or bleeding scan but pro- ceeding straight to surgery

Performing segmental ulectomics (very high rebleed rate post-op)

28 Colon and Small Bowel—Lower GI Bleeding

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