Hematochezia · What Is It, Causes, Signs, Symptoms, and More

Causes of hematochezia in adults commonly include inflammatory bowel disease (IBD), including ulcerative colitis; hemorrhoids; and bleeding from a diverticulum in the colon. Additionally, peptic ulcer disease and esophageal varices are causes of upper gastrointestinal bleeding that can produce hematochezia when severe. 

Ulcerative colitis is a subtype of inflammatory bowel disease that involves autoimmune attack of the large intestine (i.e., colon), resulting in inflammation and ulcers of the mucosal lining. Severe ulcerative colitis can result in hematochezia due to bleeding from the ulcers. 

Hemorrhoids are swollen veins in the lower rectum and can be painless or painful, depending on whether they are located internally or externally, respectively. They are usually caused by straining during bowel movements and are associated with obesity and pregnancy. When the walls of the blood vessels in the hemorrhoid stretch too thin as a result of increased pressure in the lower rectum, typically from straining, hematochezia can occur. 

Diverticulosis is a condition that occurs when small pouches (i.e., diverticulum) form and push outward through the wall of the colon, which can cause bleeding. Genetics as well as a high-fat, low-fiber diet make an individual more likely to develop diverticular pouches. 

Peptic ulcer disease occurs when the protective mucosal lining of the stomach and the duodenum of the small intestine erodes due to infection with the bacteria Helicobacter pylori (H. pylori) or long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs). If the ulcer is severe, rapid hemorrhage may occur, and immediate treatment is necessary due to the risk for hypovolemic shock. 

Esophageal varices refer to the presence of enlarged veins in the esophagus due to obstruction of flow through the portal vein, which is often caused by severe liver scarring. The backup of blood may lead to esophageal vein rupture, which presents as massive amounts of blood loss and melena (i.e,  black, tarry stools) or hematochezia. 

In older individuals, arteriovenous malformation (AVM) can lead to multiple repeated, often smaller, hemorrhages. An AVM is a vascular lesion that can occur anywhere along the GI tract, commonly in the colon and is related to advanced age; chronic kidney disease; and certain types of heart disease, such as aortic stenosis. Less common causes of colonic hemorrhage in adults include cancer and ischemic colitis (i.e., inflammation of the colon).

Causes of hematochezia in neonates include necrotizing enterocolitis and midgut volvulus. Necrotizing enterocolitis refers to the death of the tissue in parts of the colon due to decreased blood flow, and midgut volvulus occurs when the intestine becomes twisted during embryonic development.

Hematochezia may be diagnosed on patient history if the individual is seeking guidance due to the passage of blood in the stool or is experiencing associated symptoms, such as fainting or lightheadedness. The clinician can ask questions to confirm the presence of bleeding, estimate the amount and speed of blood loss, identify the source and potential causes, and determine the severity of the bleed. Diagnosis includes a full physical exam followed by more focused digital examination where a gloved, lubricated finger is inserted into the rectum to feel for anything unusual, such as growths, rectal fissures, or hemorrhoids. The clinician can order laboratory testing, including hemoglobin levels, to assess for anemia. An upper endoscopy and colonoscopy can also be performed, which are procedures where the clinician inserts a small tube with a camera through the esophagus and rectum, respectively. The procedures are typically conducted under anesthesia and allow the clinician to view where the gastrointestinal bleeding is coming from. Computer tomography (CT) angiograms can be performed to visualize the origin of blood loss, and if active bleeding is present, a nuclear red blood cell scan can be used to locate the source of gastrointestinal bleeding. A nuclear red blood cell scan uses small amounts of radioactive material to tag red blood cells (RBCs), so they can be visualized and traced throughout the body.

Hematochezia is treated by primarily restoring the individual’s blood volume to help prevent hypovolemia and shock, which are medical emergencies. The second step in treatment typically involves finding the source of bleeding. Subsequently, depending on the site and underlying cause, the clinician may use a combination of pharmacologic therapy, endoscopic cauterization (i.e., a procedure that uses a heated probe to close off bleeding vessels), and surgery. In the case of hemorrhoids, a topical treatment or suppository containing hydrocortisone can help reduce the pain. IBD can be treated with medications that control inflammation, such as aminosalicylates (i.e., balsalazide, mesalamine, olsalazine) or immunosuppressants (i.e., azathioprine and mercaptopurine). 

Diverticulosis is typically treated with supportive care, such as high fiber diets, and is likely to resolve on its own. Ischemic colitis can similarly be self-limiting and may be treated with supportive care, such as rest and intravenous fluids. If severe, antibiotics (e.g., metronidazole, ciprofloxacin) can be administered to reduce risk of infection and necrosis. 

AVM and colon cancer may require the use of more invasive approaches, such as endoscopic cauterization and surgery, respectively. Necrotizing enterocolitis is usually treated by administering a feeding tube and surgery, depending on severity. Lastly, a midgut volvulus can be reduced or untwisted with surgical intervention.