Diverticular bleeding refers to blood loss from small pouches that can develop in the lining of the digestive tract, most frequently in the colon. This condition is a common cause of bleeding in the lower digestive system. It can manifest as sudden and often substantial blood in the stool.
What Are Diverticula?
Diverticula are small, bulging pouches that form in the wall of the colon. While these sacs can develop anywhere, they are most often found in the sigmoid colon. The presence of these pouches is a condition called diverticulosis. Many individuals with diverticulosis do not experience any symptoms or problems.
These pouches form when increased pressure within the colon pushes the inner lining through weak spots in the muscular outer layer of the colon wall. These weak spots are often where blood vessels pass through the muscle layer to supply blood to the inner wall.
How Diverticula Bleed
Diverticular bleeding occurs when a small blood vessel within the wall of a diverticulum ruptures. These vessels become exposed to injury as the diverticulum forms, leading to their weakening and rupture.
The bleeding is usually arterial, meaning it originates from an artery, which can lead to sudden and significant blood loss. Chronic irritation or repeated cycles of increased pressure within the colon can induce changes in these blood vessels. These changes include a thickening of the inner layer and weakening of the middle layer, predisposing them to rupture.
Factors Increasing Bleeding Risk
Several factors can increase the likelihood of a diverticular bleeding episode. Advanced age is a contributing factor, partly due to the natural weakening of blood vessels and the colon wall over time. As people age, the prevalence of diverticula also increases.
The use of certain medications significantly elevates the risk of bleeding. Nonsteroidal anti-inflammatory drugs (NSAIDs) and aspirin can increase the risk of lower gastrointestinal bleeding, including diverticular bleeding. These medications can erode blood vessels and hinder the blood’s ability to clot effectively. Anticoagulant medications, commonly known as blood thinners, also prevent blood clotting, thereby increasing the risk and potential severity of bleeding from diverticula.
Conditions that affect blood vessel integrity also play a role. Hypertension, or high blood pressure, and cardiovascular disease are recognized as risk factors for diverticular bleeding. These conditions can contribute to changes in the structure of blood vessels, making them more prone to rupture.