Lower Gastrointestinal Bleeding in the Elderly

INTRODUCTION

Lower gastrointestinal (GI) bleeding is a significant cause of increased morbidity and mortality in the elderly. The incidence of lower GI bleeding increases with age, with a greater than 200-fold increase from the third to the ninth decade of life. The incidence of lower GI bleeding in the United States ranges from 20.5 to 27 per 100,000 persons per year, and is more common in men than women.¹ The increased incidence of lower GI bleeding in the elderly corresponds to the increased incidence of specific GI diseases, the increased incidence of comorbid illnesses, and more polypharmacy. GI illnesses associated with lower GI bleeding that are more common in the elderly include diverticulosis coli, vascular ectasia, ischemic colitis, and colonic neoplasms. Hemorrhage and the presence of serious concurrent illness are the two most important factors in predicting mortality among patients with GI bleeding.² Comorbid illnesses include atherosclerotic cardiovascular disease, cerebrovascular disease, and malignancy. Anticoagulant and nonsteroidal anti-inflammatory drug (NSAID) use increases the probability of GI bleeding.

PATHOPHYSIOLOGY OF LOWER GI BLEEDING

Lower GI bleeding can be acute bleeding, occult bleeding, or obscure bleeding. Acute lower GI bleeding presents as melena or hematochezia. Occult bleeding is usually detected with stool guaiac testing and is the most common presentation of lower GI bleeding in the elderly, occurring in 10% of the adult population. Remarkably, patients losing 100 mL of blood per day may have grossly normal-appearing stools.^3,4 Obscure bleeding is when the source of bleeding is difficult to detect on routine endoscopic and radiologic examinations. The source of bleeding is unidentified in approximately 5% of patients.⁵
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CAUSES OF LOWER GI BLEEDING

There are many causes of lower GI bleeding in the elderly. The most common causes of lower GI bleeding are diverticular disease and vascular ectasias. Less common causes of lower GI bleeding are inflammatory diseases of the colon due to infectious colitis, ischemic colitis, idiopathic inflammatory bowel disease, post-irradiation colitis, neoplasms, postpolypectomy hemorrhage, and hemorrhoids. There are additional rarer causes that include Dieulafoy’s lesion and colorectal varices.^6,7

Diverticulosis Coli

The incidence of diverticulosis coli increases with age from approximately 5% of individuals at age 40 to 65% at age 85.⁸ Although most patients with diverticulosis are asymptomatic, approximately 3-5% can develop lower GI bleeding, usually in the form of hematochezia.⁹ Diverticular disease is the most common cause of lower GI bleeding, with an incidence ranging from 15-48% of patients with lower GI bleeding, depending upon the series. Diverticular hemorrhage can be severe, with a significant morbidity rate of 10-20%. Risk factors for hemorrhage include the use of NSAIDs, lack of dietary fiber, constipation, and advancing age.^10-12 Bleeding usually ceases spontaneously, with less than 1% of patients requiring greater than 4 units of blood.⁹ However, bleeding can become more hemodynamically significant in elderly patients with comorbid conditions, such as cerebrovascular disease or atherosclerotic cardiovascular disease, and in those with polypharmacy who may be taking anticoagulants or NSAIDs.

Vascular Ectasia

Vascular Ectasia or angiodysplasia can occur in the colon and small intestine. They occur with much greater frequency in the elderly than telangiectasia, hemangiomas, or congenital arteriovenous malformations. They are degenerative lesions of previously normal blood vessels that may occur anywhere in the colon, but are more common in the cecum and right colon. Small-bowel vascular ectasia are the most common source of obscure GI bleeding, comprising up to 60% of cases.^13,14 Bleeding may manifest itself as iron-deficiency anemia and occult blood-positive stools. However, in up to 15% of patients, bleeding is massive.

Inflammatory Diseases of the Colon

The various types of inflammatory diseases of the colon can be indistinguishable upon initial presentation and endoscopic findings. The clinical presentation of abdominal pain, lower GI bleeding, fever, and dehydration are common to all. Endoscopically, the mucosa may appear edematous, friable, and ulcerated in any of the various types of colitis, although the characteristics specific to the various types of colitis can aid in diagnosis. The most common forms in the elderly are ischemic colitis, infectious colitis, idiopathic inflammatory bowel disease, and post-irradiation colitis. Ischemic colitis accounts for 3-9% of all cases of lower GI bleeding in the elderly.^1,15 Colonic atherosclerosis is almost universal in the elderly and predisposes to ischemic colitis. Ischemic colitis results from reduced blood supply to the colon from hypotension, embolic events, or anatomic or functional changes in the mesenteric vasculature. Most often, the precipitating event or factors leading to the lesion cannot be identified. However, a history of a hypotensive event supports the diagnosis.

Patients often present with lower abdominal cramping type of pain, followed by hematochezia or bloody diarrhea. Bleeding is rarely severe. It may be complicated by perforation or stricture formation that may necessitate surgery, including hemicolectomy.¹⁶ The elderly have a greater risk for infectious colitis and its complications than younger populations.¹⁷ In addition, the mortality from infectious colitis increases with age.¹⁸ The most common causes of enteric infections in the elderly are Campylobacter, Salmonella, Shigella, Escherichia coli 0157:H7, and Clostridium difficile.¹⁹ C. difficile as a cause of diarrhea and lower GI bleeding must be considered in elderly patients in long-term care facilities and hospitals, and in all patients who have recently been treated with antibiotics. Infectious colitis is suggested following the consumption of undercooked fish or meat and during outbreaks of bloody diarrhea in the community, and certainly in long- term care facilities or hospitals. E. coli 0157:H7 has significant complications, such as acute thrombotic thrombocytopenic purpura and death in the elderly. Bleeding is rarely massive in patients with infectious colitis, with hematochezia noted in less than 10% of cases.²⁰ Idiopathic inflammatory bowel disease (IBD) can occur in the elderly, although with much less frequency than in younger persons. It is less common than ischemic bowel disease in the elderly. There is a bimodality in the incidence of IBD, with a second peak occurring between the ages of 60 and 70.21 Approximately 15% of all patients with inflammatory bowel disease develop symptoms after the age of 65.^21,22 Although GI bleeding is common with IBD, severe hematochezia is infrequent. Lower GI bleeding in IBD accounts for hospitalizations in 6% of patients with Crohn’s disease and 1.4-4.2% of patients with ulcerative colitis.^23,24 Post-irradiation colitis can be a source of lower GI bleeding in the elderly population, with a greater incidence of malignancy requiring irradiation. It can present as occult or massive bleeding, or chronic iron deficiency anemia.

Neoplasms

Benign and malignant neoplasms of the colon and rectum are a cause of lower GI bleeding in 10-20% of cases in elderly patients.²⁵ Bleeding is the initial presenting symptom in up to 26% of patients with colorectal neoplasms.^26,27 Although bleeding is usually occult or mild, it may rarely present as massive bleeding if there is erosion into a large vessel or if the patient is taking anticoagulants or NSAIDs. Bleeding may often be associated with constipation or diarrhea, a change in stool caliber, or weight loss.

Post-Polypectomy Bleeding

Bleeding is a complication of colonoscopic polypectomy in approximately 0.7-2.5% of cases and is the source of bleeding in approximately 3% of patients.^28,29 It more commonly follows sessile polyp removal. Hematochezia usually develops soon after polypectomy, but may be delayed in some cases for up to 1 week after the procedure.³⁰

Hemorrhoids

Hemorrhoids are a common source of bleeding in elderly patients with intermittent and low-volume hematochezia, which often only coats the stool. Comorbid Illness After hemorrhage, the presence of the serious concurrent illness is the second most important factor in predicting mortality among patients with GI bleeding.² These include cardiovascular disease, cerebrovascular disease, and malignancy. Atherosclerotic cardiovascular disease is a cause of ischemic bowel disease. Atherosclerotic heart disease with atrial fibrillation is associated with embolic events to the intestine leading to ischemic bowel disease. Aortic valvular disease is associated with vascular ectasia of the colon. Polypharmacy The increased use of medications, such as anticoagulants and NSAIDs, among elderly persons as compared to younger individuals increases the probability of GI bleeding. Elderly patients with arthritis often use NSAIDs to a great degree, which not only causes upper GI ulceration, but also ulceration of the small intestine and colon that may bleed. Additionally, NSAIDs and anticoagulants can increase hemorrhage due to their effect on platelet function and blood-clotting factors.

CLINICAL COURSE AND DIAGNOSTIC EVALUATION

The clinical course can vary widely in elderly patients with lower GI bleeding from occult bleeding to massive life-threatening hemorrhage and death. It is often complicated by comorbidities and polypharmacy. Therefore, the evaluation is adjusted to the rate and severity of hemorrhage and the clinical status of the patient. A detailed history and physical examination is important, but may be complicated by the presence of visual, auditory, and cognitive impairment. It may be necessary to confer with the primary care provider, caregiver, and perhaps even the pharmacist to obtain history, such as extent of bleeding, duration of symptoms, presence of comorbid illnesses, prior surgical history, known drug allergies, and recent and current medication use, such as clopidogrel, warfarin, and NSAIDs. Common presenting symptoms for illnesses may not be evident. For example, in elderly patients taking NSAIDs, abdominal pain may not be a significant presenting complaint, and painless hemorrhage that may be life-threatening can occur.^31-33 Physical examination to assess the severity of bleeding and status of the patient is important, with emphasis on the presence of orthostatic changes, signs of cardiopulmonary compromise, stigmata of chronic liver disease, and evidence of coagulopathy. In cognitively impaired patients, a Mini-Mental State Examination is indicated on or after admission, if feasible. Informed consent to procedures may be difficult to obtain in patients who suffer from cognitive dysfunction. With the exception of a true life-threatening emergency, every attempt should be made to obtain consent for testing procedures from the patient, if competent, or the surrogate. In the case when a guardian cannot be reached, administrative consent should be obtained.³⁴ In patients with mild, chronic, or occult bleeding with iron-deficiency anemia, workup can be performed in a hospital or outpatient setting, depending on the clinical state of the patient. The timing of tests and the type of intervention should be custom-tailored, especially for the frail elderly patient, depending upon functional status, its impact on outcome, and the available diagnostic strategies. The various interventions considered should not be withheld because of age alone.

In the majority of cases, lower GI bleeding stops spontaneously with appropriate resuscitation and supportive care. However, in some cases it may be life-threatening and require endoscopic, radiologic, or surgical intervention. Since approximately 10-15% of patients presenting with hematochezia may have an upper GI source of bleeding, it is important to rule out an upper GI bleeding source in these patients.^35,36 Urgent colonoscopy performed within 24 hours of hospitalization following a rapid purge is the best test for evaluation of lower GI bleeding, once the patient has been resuscitated and hemodynamically stabilized.³⁷ In patients with active bleeding where colonoscopy is not feasible due to massive bleeding, radionuclide imaging and abdominal angiography can help identify the source of bleeding.^38,39 There are important considerations involving diagnostic and treatment methods in elderly patients. Older patients are more likely to have pacemakers with or without defibrillators. Recommendations for management of patients who require endoscopy and have pacemakers and internal defibrillators are not well defined. Cardiology consultation may often be indicated. Alternative means of tissue removal, destruction, or hemostasis should be considered to simplify management of patients to control hemorrhage with defibrillators, such as hemo-clips, ligation devices, and injection of epinephrine and sclerosing agents. The general principle of geriatric pharmacology of starting with low doses of medication and slowly advancing to larger doses is an important dictum in conscious sedation of the elderly during endoscopy. Initial dosages should be lower, and titration should be more gradual.⁴⁰ It is estimated that 5% of patients with GI bleeding, whether occult or overt, will have a negative upper GI endoscopy and colonoscopy. This scenario of obscure bleeding is more common in older patients.⁴¹

Radionuclide scanning and abdominal arteriography may be helpful when bleeding is sufficient to reveal a lesion. Newer endoscopic methods are available for evaluation of the small intestine, which may be an important source of either overt or occult bleeding in the elderly. Wireless capsule endoscopy is a useful tool for the diagnosis of obscure GI bleeding, enabling noninvasive visualization of the entire small intestine.⁴² Push enteroscopy and double-balloon enteroscopy can also be helpful in both the evaluation and treatment of obscure GI bleeding from the small intestine.⁴³

TREATMENT

After initial evaluation, colonoscopy provides not only the best method of evaluation, but also the best method for treating patients with lower GI bleeding. Colonoscopy provides many methods for controlling hemorrhage, including heater probe or bipolar probe thermal coagulation, band ligation, argon plasma coagulation, metallic clips, epinephrine and sclerosing agent injection, and fibrous glue. For persistent bleeding not amenable to control by colonoscopic methods, abdominal angiography with infusion of vasopressin or embolization of the bleeding vessel is successful in about 90% of cases. Embolization with polyvinyl alcohol particles or microcoils provides more definitive means of controlling the bleeding, but may be complicated by intestinal infarction in up to 20% of patients.⁴⁴ In addition, bleeding recurrence is 50%, and intolerance of the cardiovascular complications of vasopressin is common in the elderly.^45,46 Patients who fail angiographic or endoscopic therapy may require surgery. Every effort should be made to identify the bleeding source prior to referral for surgery, which often requires a blind segmental colectomy and carries a significant risk of complications in the elderly. A positive preoperative angiogram for regional localization reduces the risk of rebleeding.⁴⁵ Blind segmental resection is associated with a rebleeding rate of 47% and morbidity and mortality rate of 83% and 57%, respectively.^47-52 There are specific issues in the elderly population with comorbidities and polypharmacy.

For example, metronidazole used to treat C. difficile colitis may interfere with oxidation of warfarin and induce excessive anticoagulation. General principles for treatment of elderly patients with IBD are the same as for younger patients, although no studies specifically for the elderly population are available. There are significant complications, however, from treatment of IBD in the elderly. For example, osteoporosis is a significant problem in the elderly patients with IBD taking corticosteroids. Older patients with IBD taking these agents must be evaluated for osteoporosis and offered prophylaxis with agents such as biphosphonates and calcium with vitamin D.⁵³ In the majority of patients with lower GI bleeding, bleeding is controlled or ceases spontaneously, with less than 1% of patients requiring a transfusion of greater than 4 units of blood.⁹ Jensen et al²² reported no rebleeding during a 30-month follow-up after endoscopic therapy when compared to a 53% rebleeding rate in patients treated with conservative medical therapy alone. However, despite improvements of localization of bleeding and targeted treatment of lesions, the mortality rate for severe bleeding remains 10%.⁴⁵

CONCLUSION

Lower GI bleeding is a significant cause of increased morbidity and mortality in the elderly population. The incidence increases with age and corresponds to the increased incidence of specific GI diseases more common in the elderly, the increased incidence of comorbid illness in this population, and polypharmacy, which is more common in the elderly. With appropriate evaluation and management, a successful outcome will be achieved in the majority of elderly patients with lower GI bleeding.