Acute Lower GI Bleeding Secondary to

Rectal Ulcers

Submitted by Michael L. Wells, MD

Mayo Clinic Rochester, MN

SAR GI Bleeding DFP

Clinical History:

49 year old male with past medical history of:

Autosomal dominant polycystic kidney disease, aortic valve

replacement (on anticoagulation), ischemic colitis, gastric ulcers.

Admitted for placement of dialysis catheter. - New onset bright red blood per rectum while in hospital.

- Started oral colon prep for planned colonoscopy +/- EGD.

- Partially through the oral prep, the rectal bleeding increased and he

became dizzy with dropping blood pressure.

- CT angiogram ordered due to suspected rapid bleeding and low

likelihood of completing the colon prep.

GI Bleeding

Arterial Portal

Virtual NonContrast

Arterial Portal

Virtual NonContrast

Luminal contrast accumulation arising from the low rectal wall

The collection increases in size and changes shape on the portal phase, indicating active hemorrhage.

Virtual noncontrast image shows only high attenuation hematoma in the rectal lumen

Multiple actively bleeding rectal ulcers were identified and treated with endoscopic clipping and epinephrine injection.

Knowing the location of the bleeding allowed for targeted colonoscopy, despite the incomplete colon preparation.

Teaching Points:

CT angiography and fluoroscopic angiography are acceptable methods to evaluate

suspected acute lower GI bleeding when:

- Colonoscopy is contraindicated, OR

- When a patient is unlikely to complete their oral colon preparation.

Depending on the time of day and institution, CT may be faster to obtain than a

fluoroscopic exam. In the setting of a truly unstable patient, fluoroscopic angiography

would be a more appropriate choice due to its potential for therapeutic intervention.

CT angiography can identify the location and potential cause of GI bleeding. This

information is helpful for choosing the best interventional modality.

GI Bleeding

Teaching Points:

Active hemorrhage can be identified by: Detecting a new contrast collection when comparing with precontrast or virtual

noncontrast series OR by detecting a change in attenuation and shape between

contrast enhanced phases.

The differential diagnosis for the bleeding in this case would include:

Hemorrhoids

Anorectal fissures or ulcers

Vascular malformations

These are the most common causes of lower GI bleeding in patients

< 50 years old.

GI Bleeding

References

1.Barnert J, Messmann H. Diagnosis and management of lower gastrointestinal

bleeding. Nat Rev Gastroenterol Hepatol 2009;6(11):637–646

2. Wells M, Hansel H, Bruining D, Fletcher J, Froemming A, Barlow J, Fidler J. CT for

evaluation of acute gastrointestinnal bleeding. Radiographics 2018;38(4):1089-1107

3.Sun H, Hou X, Xue H, Li X, Jin Z, Qian J, Yu J, Zhu H. Dual-source dual-energy CT

angiography with virtual non-enhanced images and iodine map for active

gastroitestinal bleeding: Imaging quality, radiation dose and diagnostic performance.

Eur J Radiology 2015;84:884-891

GI Bleeding