Diverticular disease is a common condition of the large intestine, or colon, that affects a significant portion of the aging population. This disease involves the formation of small, bulging pouches, known as diverticula, that push outward through weak spots in the colon wall. The presence of these pouches is called diverticulosis, which often causes no symptoms and may go undetected. When one or more of these pouches become inflamed or infected, the condition is then classified as diverticulitis. While diverticulitis is associated with pain and fever, the structural condition of diverticulosis is the source of significant bleeding, known as diverticular hemorrhage.
Diverticulosis Versus Diverticulitis: Identifying the True Source of Bleeding
Diverticular bleeding is the most frequent cause of massive bleeding from the lower gastrointestinal tract. The mechanism behind this hemorrhage is structural, originating from the pouches present in diverticulosis, not the inflammation of diverticulitis. The diverticula form at points in the colon wall where small blood vessels penetrate the muscle layer to supply the inner lining.
As the pouch bulges outward, the small artery that runs across the dome of the diverticulum becomes draped over the sac, separated from the colon’s interior only by a thin layer of tissue. Chronic injury from the passage of stool within the colon can lead to the erosion of this small blood vessel. When this vessel finally ruptures, it results in the sudden, often large volume of blood characteristic of a diverticular hemorrhage.
Diverticulitis involves inflammation and sometimes infection of the pouch, causing symptoms such as severe abdominal pain, nausea, and fever. While inflammation can cause minor, occult bleeding, diverticulitis itself rarely leads to the massive hemorrhage seen in diverticular bleeding. The primary issue is the structural defect in the blood vessel within the pouch, which is a complication of diverticulosis. This bleeding can occur even in people who have never experienced an episode of diverticulitis.
Recognizing the Signs of Diverticular Hemorrhage
The symptoms of diverticular hemorrhage involve the abrupt onset of bleeding from the rectum. The blood is usually bright red or maroon, indicating the source is in the lower part of the colon. This presentation of blood passed through the rectum is medically termed hematochezia, and it often includes large amounts of blood mixed with gelatinous clots.
A distinguishing feature of this bleeding is that it is usually painless, though some individuals may experience mild abdominal cramping or a strong urge to defecate. The volume of blood lost can be significant and may cause a person to feel dizzy or weak because of acute volume loss. Diverticular bleeding is the most common cause of brisk hematochezia in the lower gastrointestinal tract.
In the majority of cases, the bleeding is self-limiting and stops spontaneously without medical intervention. Once a person has experienced an episode of bleeding, the risk of a recurrent bleed increases significantly. Bleeding from the right side of the colon may appear darker or maroon, while bleeding from the left side is more likely to be bright red.
Immediate Steps for Severe Bleeding
While most diverticular bleeding stops naturally, any episode of significant rectal bleeding must be evaluated by a healthcare professional immediately. A severe bleed can result in hemodynamic instability, meaning the body is struggling to maintain adequate blood pressure and circulation. Signs of severe blood loss that warrant emergency action include feeling faint, dizzy, or lightheaded, especially when standing up, or having a rapid heart rate.
If the bleeding is massive, continuous, or accompanied by signs of shock, such as confusion or a very fast pulse, the patient should call emergency services or proceed to the nearest emergency room. Upon arrival at the hospital, the immediate focus is on stabilization, which involves maintaining the patient’s airway and providing oxygen. Intravenous access is established quickly to administer fluids to restore blood volume.
Blood tests are performed to measure levels of hemoglobin and hematocrit, and blood is typed and cross-matched in case a transfusion is necessary. This initial stabilization is followed by diagnostic procedures to locate and stop the source of the hemorrhage. Patients with severe, ongoing bleeding may require admission to an intensive care unit for close monitoring.