Small, bulging pockets called diverticula can develop in the wall of the large intestine (colon). The presence of these pouches is a common condition known as diverticulosis, which often causes no symptoms. When these sacs become infected or inflamed, the condition progresses to diverticulitis, causing a distinct pattern of abdominal pain.
Pinpointing the Primary Pain Location
Abdominal pain concentrated in a specific region is the most frequent symptom. For a majority of people in North America and Europe, the pain is felt distinctly in the lower left quadrant (LLQ) of the abdomen. The pain is often described as persistent, sometimes lasting for several days, and can range from mild tenderness to a sudden, severe ache.
Diverticulitis pain typically localizes in the bottom-left section. While the LLQ is the default location, exceptions exist that can complicate diagnosis. A smaller percentage of people, particularly those of Asian descent, often experience pain localized in the lower right quadrant instead. This variation is due to a difference in the most common location of the diverticula within the colon.
The Anatomical Reason for Pain
The pain settles in the lower left quadrant due to the anatomy of the large intestine. In Western populations, diverticula most commonly form in the sigmoid colon, the S-shaped segment situated in the lower left side of the abdomen.
When small pieces of stool or bacteria become trapped within a diverticulum, it can lead to localized irritation, inflammation, and potential infection. The resulting inflammatory response causes the intense, localized tenderness and pain that characterizes a diverticulitis flare. In some instances, the inflammation can cause a tiny tear in the wall of the pouch, which further intensifies the localized pain. This mechanism explains why the pain is consistently focused on the site of the inflamed sigmoid colon.
Knowing When Pain Requires Immediate Medical Care
While many episodes of diverticulitis are uncomplicated and can be managed with rest and dietary changes, certain symptoms signal a more serious situation that requires immediate medical attention. The pain may be accompanied by systemic signs of a spreading infection or complication, which can rapidly worsen the patient’s condition. A high fever, typically defined as a temperature exceeding 100.4 degrees Fahrenheit, combined with chills, suggests the infection has become significant.
Persistent vomiting or severe nausea that prevents keeping fluids down is also a serious concern, as it can indicate an intestinal blockage or severe dehydration. A sudden and severe increase in abdominal pain, especially if the entire abdomen becomes rigid or board-like to the touch, may suggest a rupture of the inflamed pouch and the development of peritonitis. Any sign of significant bleeding, such as large amounts of bright red blood in the stool, also warrants an immediate trip to the emergency room for evaluation and urgent treatment.