Lower gastrointestinal bleeding case file

Lower Gastrointestinal Bleeding Case File

Eugene C. Toy MD, Donald Briscoe, MD, FA  AFP, Bruce Britton, MD, Joel J. Heidelbaugh, MD, FA  AFP, FACG

Case 23

A 62-year-old man presents to your office for a routine evaluation. His only complaint is of fatigue over the past 2 to 3 months despite no changes in diet or lifestyle. On questioning, the patient reports that he has never smoked and admits to an increase in his consumption of alcohol upon retiring, to about two to three beers per day. He has occasional headaches on the day after a night of heavy drinking, which are easily relieved by the use of over-the-counter nonsteroidal anti-inflammatory drug (NSAID) preparations. While talking to the patient and examining his chart, you note no distress and proceed with your examination. You note a 4-lb weight loss since his last visit 6 months ago and a relative increase in his pulse with a blood pressure of 129/81 mm Hg. Remarkable to this visit is the paleness of his conjunctivae, but the rest of his general examination is unchanged from the previous examination. You perform a digital rectal examination and find a smooth, normal-size prostate and some soft, reducible protrusions within the internal sphincter, along with guaiac-positive stools. You decide on a more direct approach and delve into his drinking, bowel habits, and NSAID use. His only addition is the occasional production of bloody stools accompanied by some diffuse abdominal discomfort.

⯈ What is the most likely diagnosis?

⯈ What is your next diagnostic step?

⯈ What is the next step in therapy?

ANSWER TO CASE 23:

Lower Gastrointestinal Bleeding

Summary: A 62-year-old man presents to your office for a routine checkup. He reports having occasional bloody stools and you discover guaiac-positive stools. He is a bit pale, but hemodynamically stable at the moment. You decide that further evaluation of this bleeding is necessary, but most of it can be carried out on an outpatient basis with close follow-up.

• Most likely diagnosis: Hemorrhoids.
• Next diagnostic step: Complete blood count (CBC) and colonoscopy.
• Next step in therapy: Discontinue NSAID use and decrease alcohol consumption.

ANALYSIS

Objectives

1. Know how to recognize the subtle signs and symptoms of lower gastrointestinal (GI) bleeding.
2. Understand the etiologies of lower GI bleeding.
3. Understand how to correctly evaluate and treat patients with lower GI bleeding in outpatient settings.

Considerations

This 62-year-old man presented to your office for a routine examination but was found to have some type of lower gastrointestinal bleeding that needs further evaluation. During his office visit there are no signs of hemodynamic instability or active bleeding that require immediate referral to an emergency room (ER) or inpatient treatment, so you decide on close outpatient follow-up during his workup. His immediate identifiable and modifiable risk factors for GI bleeding include the regular consumption of alcohol and NSAIDs. You counsel him on both these matters and send him to the laboratory for a CBC, chemistry panel, liver function tests, and coagulation profile prior to his discharge home from your office. Barring any abnormal laboratory values that require emergent management, you schedule him for an outpatient colonoscopy later in the week. Your differential diagnosis at this time is wide but you start to consider the most frequent offenders in his age group, which include diverticular disease, hemorrhoids, tumors, and ulcerative colitis. For the time being, you modify those factors that may contribute to any of these etiologies and await the results of his laboratory tests.

Approach To:

Lower Gastrointestinal Bleeding

DEFINITIONS

HEMATOCHEZIA: Bright red blood visible in the stool.

LOWER GI BLEEDING: Bleeding that comes from a source distal to the ligament of Treitz.

CLINICAL APPROACH

The manifestations of GI bleeding depend on the source, rate of bleeding, and underlying or coexisting disease. An older patient, or someone with significant comorbidities, such as coronary artery disease, would be at a higher risk of presenting in shock. A younger, healthier individual may present with symptoms such as fatigue or dyspnea on exertion, or may complain directly of seeing blood in the stool. Signs and symptoms of anemia are common and include weakness, easy fatigability, pallor of the conjunctivae or skin, chest pain, dizziness, tachycardia, hypotension, and orthostasis.

A history of blood in the stool or finding guaiac-positive stool on examination should prompt further evaluation to determine the source of the bleeding. Depending on a patient's history and hemodynamic status, more immediate and invasive measures may be necessary once GI bleeding is identified. For example, hematochezia is usually pathognomonic of lower GI bleeding, but can also be found in patients with heavy upper GI bleeding. In this setting, a nasogastric aspirate may help differentiate this small subset of patients.

It is critical to transport unstable patients who present with GI bleeding to the ER for hospitalization. Intensive care unit (ICU) admission should not be delayed in those with severe bleeding and a team approach, consisting of a gastroenterologist, a surgeon with expertise in GI surgery, and skilled nursing, should always be anticipated. Major causes of morbidity and mortality in patients with GI bleeding include blood aspiration and shock. To prevent these complications, endotracheal intubation should always be considered to protect the airway of patients with altered mental status. Most cases of lower GI bleeding do not warrant emergency therapy, but be prepared for decompensation in the elderly and in those with borderline normal hemodynamic parameters.

Diagnosis

The test of choice for the determination of the source of lower GI bleeding is colonoscopy. Adequate bowel preparation with an oral sulfate purge to clear the bowel of blood, clots, and stool increase the yield in diagnosing colonic bleeding sites. Angiography and technetium-labeled colloid or red blood cell scans may be of value if colonoscopy cannot be performed or if heavy bleeding prevents adequate visualization of the colon. However, the magnitude of bleeding required to show the bleeding site limits their usefulness. Sigmoidoscopy with air-contrast barium enema x-rays may be an alternative when colonoscopy is unavailable or if the patient refuses colonoscopy. If the initial sigmoidoscopy is negative, a colonoscopy must be performed. If both of these studies are negative, panendoscopy should be carried out. Capsule endoscopy has a diagnostic yield of 61 % to 7 4% and can be done when source of bleeding is still elusive after both upper and lower GI endoscopy.

Always consider the possibility of upper GI bleeding as a source of hematochezia. An aspirate from a nasogastric tube can help to make this determination. An aspirate that shows bile but not blood will help to confirm that the bleeding is from a lower GI source.

ETIOLOGIES

The most common causes of lower GI bleeding include hemorrhoids (59%), colorectal polyps (38%-52%), diverticulosis (34%-51%), colorectal cancer (8%), ulcerative colitis, arteriovenous malformations, and colonic strictures. Percentages vary among age groups and most serious causes are expected in the elderly.

Hemorrhoids

Hemorrhoids are dilated veins in the hemorrhoidal plexus of the anus. They are defined as "internal" if they arise above the dentate line and "external" if they arise below the dentate line. Both can be the cause of hematochezia. Chronic constipation, straining for bowel movements, pregnancy, and prolonged sitting ( eg, truck drivers) are risk factors. Along with bleeding, external hemorrhoids can cause pain, irritation, and a palpable lump. Internal hemorrhoids can cause bleeding and can prolapse through the anus. Conservative treatment with a high-fiber diet, stool softeners, and precautions against prolonged straining are usually successful. When necessary, various surgical procedures can be performed for definitive treatment.

Diverticular Disease

Diverticula are outpouchings of the colonic mucosa through weakened areas of the colon wall. They occur most often where blood vessels penetrate through the muscles of the colon. They are most often asymptomatic and found on endoscopy or bowel imaging studies. They can cause symptomatic, and occasionally massive, bleeding that is usually painless. Diverticular bleeding occurs in 10% to 20% of cases of lower GI bleeding, with most cases being increased by NSAID or aspirin use. In diverticular disease, bleeding is often self-limited and ceases approximately 75% of the time, while recurring at a rate of approximately 38%. When the bleeding is extremely heavy or fails to stop, surgical resection of the affected portion of the colon may be necessary. Asymptomatic diverticulosis is managed with dietary modification, primarily a high-fiber diet.

Diverticulitis is a painful inflammation and infection of a diverticulum. Diverticulitis frequently causes left lower quadrant abdominal pain along with fever, nausea, diarrhea, and constipation. Perforation of a diverticulum resulting in peritonitis or intra-abdominal abscess formation can be a complication. Diverticulitis is typically treated with bowel rest and antibiotics effective against gut flora. A combination of a quinolone and an agent for anaerobic organisms, such as metronidazole, is one commonly used regimen. In severe cases, recurrent cases, or when perforation occurs, surgery is indicated.

Inflammatory Bowel Disease

Ulcerative colitis and Crohn disease are the two primary diagnoses considered in the category of inflammatory bowel disease (IBD). Ulcerative colitis causes continuous inflammation of the large bowel, starting from the rectum and extending proximally. Severe disease can cause pancolitis, affecting the entire colon. Crohn disease causes areas of focal inflammation, but can occur anywhere in the gastrointestinal tract. Both diseases can cause recurrent episodes of abdominal pain, diarrhea, weight loss, rectal bleeding, fistulas, and abscesses. The definitive etiology of IBD is not known, but these are autoimmune syndromes and a family history of IBD is a major risk factor. Along with GI symptoms, numerous extraintestinal manifestations may occur, most frequently arthritis. Other extraintestinal manifestations include sclerosing cholangitis, cirrhosis, fatty liver, pyoderma gangrenosum, and erythema nodosum. Ulcerative colitis is a significant risk factor for the development of colon cancer. Patients with ulcerative colitis require frequent surveillance colonoscopic examinations. IBD can be managed with symptomatic therapy, such as antidiarrheal medications, along with anti-inflammatory medications (aminosalicylates, corticosteroids) given orally or as enemas, and immunosuppressive medications. Ulcerative colitis can be definitively treated with a total colectomy, which is usually reserved for severe pancolitis, failure to respond to medical therapy, or because of the risk of colon cancer.

Colon Neoplasms

Polyps are benign neoplasms of the colon. Hyperplastic polyps tend to be small, smooth growths found incidentally during endoscopy and are of no prognostic significance. Adenomatous polyps are benign growths that have a potential to become malignant. Listed in order of potential for becoming cancerous (from least to most), the three types of adenomas are tubular adenomas, tubulovillous adenomas, and villous adenomas. Larger polyps have a higher risk of causing bleeding and becoming malignant than smaller polyps. Polyps can be identified and removed during endoscopic procedures.

Colon cancer is the third most common cancer and the second leading cause of cancer deaths in men and women. The risk of colon cancer increases with age, with a history of colon polyps, a family history of colon cancer, or a personal history of ulcerative colitis. Any patient older than age 50, who has lower GI bleeding, must be evaluated for the presence of colon cancer. Because of the presence of premalignant lesions (polyps) that can be identified and removed in asymptomatic patients, colon cancer screening is recommended for all adults older than age 50, and at younger ages for those with increased risks. The treatment and prognosis of colon cancer depends on the stage in which it is found. The Dukes System stages colon cancer from A to D, depending on the penetration through the bowel wall layer, the presence of lymph node spread, and distant metastases. Dukes A colon cancer has an excellent prognosis with surgical resection; Dukes D cancer is usually not curable and is treated with combinations of surgery, chemotherapy, and radiation.

CASE CORRELATION

• See also Case 9 (Geriatric Anemia).

COMPREHENSION QUESTIONS

23.1 A 52-year-old man presents with bright red blood per rectum. He states that he has been bleeding heavily for a couple of hours. In the ER, his pulse is 110 beats/min, blood pressure is 90/50 mm Hg, he is cool and clammy appearing, and he has blood present on rectal examination, although he does not appear to be bleeding at the present. Which of the following is the best initial next step?

A. Colonoscopy.

B. Flexible sigmoidoscopy.

C. Place a nasogastric tube.

D. Start a bolus of IV normal saline.

E. Give a transfusion of type O-negative blood.

23.2 On a screening colonoscopy, a patient is noted to have several diverticuli in the sigmoid colon. He has never had any complaints of constipation, diarrhea, abdominal pain, or rectal bleeding. Which of the following is the best step in the management of this patient?

A. Annual colonoscopy

B. Sigmoid colectomy

C. High-fiber diet

D. Proton pump inhibitor

23.3 A 25-year-old man has a colonoscopy for diagnostic evaluation of abdominal pain, weight loss, diarrhea, and blood in the stool. The colonoscopy shows diffuse mucosa! inflammation in the anus and descending colon. Which of the following is the most likely diagnosis?

A. Ulcerative colitis

B. Crohn disease

C. Pseudomembranous colitis

D. Colon cancer

ANSWERS

23.1 D. The initial evaluation of this acutely ill patient is "ABC" -airway, breathing, and circulation. As he appears to be in hypovolemic shock, with tachycardia and hypotension, a bolus of a crystalloid fluid, such as normal saline or lactated Ringer solution, is necessary before proceeding with any of the other evaluations.

23.2 C. Asymptomatic diverticuli are a common finding on screening colonoscopies. The initial management of this is a high-fiber diet. Diverticulosis by itself does not increase one's risk of developing colon cancer. Surgery is typically reserved for severe or recurrent symptomatic cases.

23.3 A. Ulcerative colitis causes continuous inflammation of the colon anywhere from rectum only to the entire colon, whereas Crohn disease causes patchy inflammation with skip areas throughout the alimentary canal but often the ileum and right side of colon. Pseudomembranous colitis is a complication of Clostridium difficile infection of the colon.

CLINICAL PEARLS

⯈ Lower GI bleeding is usually suspected in lesions or pathology that is distal to the ligament of Treitz. Simple measures like nasogastric lavage can aid in ruling out upper GI bleeding as a cause of hematochezia.

⯈ In a patient with acute lower GI bleeding, consider performing colonoscopy. Other diagnostic procedures that may be useful include radionuclide imaging and mesenteric angiography.

⯈ Any patient older than 50 years should be screened for colon cancer. If a patient has a family history of colon cancer, colonoscopy screening should be performed 10 years prior to the age of diagnosis in the relative, or at age 50, whichever comes first.

REFERENCES

Ahmed R, Gearhart SL. Diverticular disease and common anorectal disorders. In: Kasper D, Fauci A, Hauser S, et al., eds. Harrison's Principles of Internal Medicine.19th ed. New York, NY : McGraw-Hill; 2015. Available at: http://accessmedicine.mhmedical.com. Accessed May 25, 2015. 

Anthony T, Penta P, Todd RD, et al. Rebleeding and survival after acute lower gastrointestinal bleeding. Am] Surg. 2004;188:485-490. 

Bull-Henry K, Al-Kawas FH. Evaluation of occult gastrointestinal bleeding. Am Fam Physician. 2013 Mar 15;87(6):430-436. 

Fargo MY, Latimer KM. Evaluation and management of common anorectal conditions. Am Fam Physician. 2012 Mar 15;85(6):624-630. 

Friedman S, Blumberg RS. Inflammatory bowel disease. In: Kasper D, Fauci A, Hauser S, et al., eds. Harrison's Principles of Internal Medicine.19th ed. New York, NY: McGraw-Hill; 2015. Available at: http://accessmedicine.mhmedical.com. Accessed May 25, 2015.

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