Diverticulitis is a common digestive condition involving the inflammation or infection of small, bulging pouches (diverticula) that form in the lining of the large intestine. While abdominal pain is the expected symptom, many people wonder, “Can diverticulitis cause leg pain?” The answer is yes, though it is not typical. This link between the colon disease and pain radiating into the hip, groin, or leg points toward specific anatomical relationships or, sometimes, a serious complication.
Understanding Diverticulitis
Diverticulitis occurs when one or more of the small pouches (diverticula) in the colon wall become inflamed or infected. These pouches usually form in the large intestine, a condition known as diverticulosis. Diverticulitis most frequently affects the sigmoid colon, the final portion of the large intestine before the rectum.
Because of this common location, the characteristic pain is usually felt in the lower left quadrant of the abdomen. Beyond localized abdominal pain, common symptoms often include a fever, nausea, and vomiting. Patients may also notice a change in their bowel habits, experiencing either constipation or diarrhea.
The Direct Connection Between Diverticulitis and Leg Pain
The primary mechanism linking diverticulitis to pain in the leg or groin involves the close anatomical proximity of the inflamed colon to other structures. The sigmoid colon, where diverticulitis frequently occurs, sits near the back wall of the abdomen, an area known as the retroperitoneum. The inflammation from the infected colon pouch can easily irritate nearby muscles and nerves in this space.
Specifically, the inflamed colon can lie directly against the psoas muscle, a long muscle that runs from the lower spine down through the pelvis to the upper thigh bone. When the psoas muscle becomes irritated due to the adjacent colonic inflammation, it can involuntarily spasm or tighten. This condition, sometimes referred to as the Psoas Sign, can cause pain that radiates along the muscle’s path. The pain is often felt in the hip, groin, and sometimes the upper front of the thigh, mimicking a muscle strain or nerve issue.
This discomfort is a form of referred pain, where the brain interprets the pain signal as coming from a location other than its true source. The localized inflammation near the psoas muscle can be significant enough to cause this radiating sensation. The pain typically worsens when stretching the hip or leg, which further compresses the irritated structures.
Serious Complications Leading to Leg and Groin Pain
When diverticulitis progresses beyond simple, localized irritation, it can lead to severe complications that definitively cause deep leg and groin pain. An infected diverticulum can rupture, leading to the formation of a contained pocket of pus called an abscess. If this abscess forms in the retroperitoneal space, it can track downward along the psoas muscle sheath.
This tracking abscess creates a direct pathway for infection to spread from the abdomen into the upper leg. The resulting condition, known as a psoas abscess, causes intense, deep pain in the hip and thigh, often making it difficult or impossible to move the leg. In rare, severe cases, the infection can progress to necrotizing soft tissue infection, where bacteria destroy the muscle tissue, a condition called necrotizing myositis.
Another severe complication is the formation of a fistula, an abnormal tunnel that develops between the infected colon and another structure. While fistulas often connect to the bladder or vagina, they can, in rare instances, create a path for infection to reach the soft tissues of the hip and thigh. This can result in a soft tissue infection or abscess in the lower extremity. These severe scenarios explain why leg pain can be the predominant or even the only presenting symptom of complicated diverticulitis.
When Leg Pain Requires Immediate Medical Attention
When leg or groin pain occurs alongside a known or suspected diverticulitis flare, certain symptoms serve as clear red flags indicating an urgent medical situation. A high fever, typically above 100.4°F, accompanied by shaking chills, suggests a severe infection or abscess formation that may be spreading systemically.
If the leg pain is associated with significant, unexplained swelling, redness, or warmth in the hip or thigh, it may indicate a tracking abscess or serious soft tissue infection. An inability to move the leg normally, or an inability to bear weight on the affected side, warrants immediate evaluation. This mechanical inability suggests the infection is physically impacting the psoas muscle or surrounding tissues.
Any signs of systemic infection, such as rapid heartbeat, low blood pressure, or sudden confusion, are signs of sepsis and require emergency care. If the abdominal pain suddenly worsens or becomes widespread, this could signal a perforation of the colon. When leg pain is the primary or most severe symptom, especially without typical abdominal symptoms, it is crucial to consult a healthcare provider immediately to rule out a severe, tracking infection.