A 52-year-old white male presented to the emergency room (ER) with a chief complaint of “passing blood from my rectum.” The bleeding was acute in onset and began approximately 18 hours ago. He has had a total of four episodes of bright red blood per rectum. In the first two episodes, he passed a mixture of stool and blood; however, in the two most recent episodes, he passed only blood. He describes each episode as a “large amount of blood.” He has no other symptoms, including no abdominal pain. In the ER, his initial heart rate was 110, and his blood pressure was 98/64. He received one liter of normal saline with a decrease in his heart rate to the low 90s and improvement in his blood pressure to 110/70. Hemoglobin on presentation was 11.2. He had a normal complete blood count (CBC) and comprehensive metabolic panel (CMP) one year ago. The last colonoscopy was two years ago; it was negative for polyps and cancer. He was told he had “pockets” in his colon. He has well-controlled hypertension on lisinopril 20 mg po daily.
What is the most likely etiology for this patient’s lower GI bleeding? Please select one correct answer from the choices below:
A) Ischemic colitis
B) Diverticular bleeding
C) Internal hemorrhoids
D) Infectious colitis
The correct answer is B, diverticular bleeding.
Practice Pearls
Colonic diverticular bleeding accounts for 30 to 50 percent of large volume rectal bleeding cases; it is the most common cause of brisk hematochezia. Risk of bleeding among patients with diverticulosis is 0.5 per 1,000 person-years. Risk of bleeding increases with time. Risk factors for bleeding include age 70 or above, bilateral diverticulosis, nonsteroidal anti-inflammatory drug use, hypertension, patients on anticoagulation and obesity.
Bleeding diverticula have a distinctive angioarchitecture, characterized by blood vessels becoming draped over the dome of the diverticula, separated from the lumen only by mucosa. If, for any reason the vessel wall is exposed due to mucosal injury along the luminal aspect, it may result in a bleeding episode from that diverticulum. The right colon is the most common site of colonic diverticular bleeding, accounting for 50 to 90 percent of patients. (This is in distinction to diverticulitis, where the left colon is the most common site.) Bleeding resolves spontaneously in 75 percent of patients, but one episode of bleeding appreciably increases risk of future rebleeding (25 to 40 percent within four years).
Typically, patients with diverticular bleeding are older with multiple comorbidities. Morbidity and mortality rates together are 10 to 20 percent.
The typical clinical presentation of diverticular bleeding is painless hematochezia. If patients have symptoms, it is usually secondary to the cathartic effect of blood in the colon. Symptoms include abdominal cramping and urge to defecate as well as dizziness or feeling weak due to acute blood and volume loss. Bleeding from left colon diverticulosis is typically bright red; bleeding from the right colon appears dark or maroon.
The diagnosis of diverticular bleeding can be made with colonoscopy, tagged red blood cell scan, computed tomography angiography and angiogram. Colonoscopy and angiography potentially provide both diagnostic and therapeutic options.
Management of diverticular bleeding includes resuscitation upon arrival in the ER with two large bore IVs and assessment of the patient’s hemodynamic status and need for IV fluids/blood products. Lab studies include CBC, CMP and prothrombin time/international normalized ratio. Medications should be reviewed for anticoagulants and thienopyridines. Any coagulopathy should be corrected.
Patients with diverticular bleeding should undergo colonoscopy to attempt to identify the bleeding diverticulum (which can be difficult). If the bleeding diverticulum is identified at colonoscopy, therapeutic options include epinephrine injection, bipolar coagulation, clipping and banding.
Angiography is typically reserved for cases when the bleeding diverticulum cannot be identified by colonoscopy or when therapeutic colonoscopy was unsuccessful in treating the bleeding. Angiographic therapeutics include embolization (mechanically occlude bleeding site) or infusion of vasoconstricting agents.
Surgical intervention is reserved for patients who have ongoing bleeding despite colonoscopic and angiographic attempts to control the bleeding. A segmental resection is typically performed based on the findings from colonoscopy and imaging studies.
Katelyn Cookson, PA-C
UCHealth Digestive Health Center
Aurora, CO
Joseph Vicari, MD, MBA, FASGE
Rockford Gastroenterology Associates
Rockford, IL
Katelyn Cookson, PA-C, is a physician assistant specializing in gastroenterology at UCHealth Digestive Health Center and is also an instructor at the University of Colorado Anschutz Medical Campus. Joseph Vicari, MD, F91Ƶjoined Rockford Gastroenterology in 1997 and has served as managing partner. He previously served as chair of the 91ƵPractice Operations Committee and currently serves as councilor on the 91ƵGoverning Board.
UpToDate Colonic Diverticular Bleeding. Retrieved from the UptoDate.com website, https://www.uptodate.com
91Ƶguideline. The role of endoscopy in the patient with lower GI bleeding. GIE Journal. 2014;79(6):875-885
91Ƶguideline. The management of antithrombotic agents for patients undergoing GI endoscopy. GIE Journal. 2016;83:3-16
American College of Gastroenterology-Canadian Association of Gastroenterology Clinical Practice Guideline: Management of anticoagulants and antiplatelets during acute gastrointestinal bleeding and the periendoscopic period. The American Journal of Gastroenterology. 2022;117(4):542-558