Diverticulitis occurs when small, bulging pouches in the lining of the large intestine, known as diverticula, become inflamed or infected. The presence of these pouches, called diverticulosis, is common, particularly in older adults, but usually causes no symptoms. When inflammation occurs, it results in diverticulitis, a condition that typically causes abdominal pain. This article explores the anatomical connections and complications that can link this internal inflammation to discomfort experienced in the buttock area.
Where Diverticulitis Pain Typically Occurs
Pain associated with diverticulitis most frequently begins in the lower left side of the abdomen. This location corresponds to the sigmoid colon, the lower portion of the large intestine where diverticula most commonly form. The pain can manifest suddenly or develop gradually over several days, often described as a constant ache.
The intensity of this abdominal pain varies significantly, ranging from mild tenderness to severe discomfort. This discomfort often correlates with the degree of inflammation within the colon wall. Other common symptoms include fever, nausea, and changes in bowel habits, such as constipation or diarrhea.
How Diverticulitis Can Lead to Buttock Pain
While the inflamed colon is situated in the abdomen, the pain signal can travel along shared pathways, leading to discomfort perceived elsewhere. This phenomenon, known as referred pain, occurs because internal organs and areas like the lower back and gluteal region utilize common sensory nerves that feed into the spinal cord. Inflammation in the deep pelvic area, where the sigmoid colon lies, can “confuse” the nervous system, causing the brain to register the pain in the buttock or lower back.
More serious complications can create a direct physical link between the intestinal inflammation and the gluteal region. A severe infection can lead to the formation of an abscess, a localized collection of pus, adjacent to the colon. If this abscess is located deep within the pelvis, it can irritate or press upon nearby structures, including the muscles and nerves that extend toward the hip and buttock.
In rare and complicated cases, the infection can track outward from the colon, creating an abnormal tunnel called a fistula. These fistulas can extend from the bowel to other adjacent organs or even to the skin. In extremely unusual instances, a fistula can track through the pelvic floor and present as an abscess or drainage near the perianal area or deep within the gluteal muscle, directly causing severe buttock or perianal pain. Such a complication represents a significant progression of the disease.
Non-Gastrointestinal Reasons for Buttock Pain
Buttock pain is frequently musculoskeletal or neurological in origin and is often unrelated to the digestive tract. One of the most common causes is sciatica, which is not a diagnosis itself but a symptom describing pain radiating along the sciatic nerve. Sciatica often results from a problem in the lower spine, such as a herniated disc or spinal stenosis, which compresses one of the nerve roots. This compression typically causes a sharp, shooting pain that begins in the lower back or buttock and travels down the back of one leg, sometimes accompanied by numbness or weakness.
Another frequent cause of gluteal pain is Piriformis Syndrome, which is often confused with true sciatica because the symptoms are similar. This condition occurs when the piriformis muscle, a small muscle situated deep in the buttock, spasms or tightens. Since the sciatic nerve runs either directly beneath or sometimes through this muscle, the spasm can irritate or compress the nerve.
Piriformis Syndrome usually results in a deep, aching pain localized mainly in the buttock, and it may radiate down the back of the thigh, though often not past the knee. The pain is typically aggravated by prolonged sitting, climbing stairs, or running. General lower back strain, resulting from muscle injury or ligament sprain, can also refer pain to the buttocks, as the stabilizing muscles of the lumbar region and pelvis are interconnected.
Warning Signs Requiring Prompt Medical Evaluation
Any persistent and unexplained abdominal or buttock pain warrants consultation with a healthcare provider for proper diagnosis. However, certain symptoms indicate a severe complication of diverticulitis and require immediate medical attention.
A high fever, typically above 100.4°F (38°C), accompanied by chills or rigors, suggests that the infection has spread beyond the immediate site of the colon. Severe, unrelenting pain in the abdomen, low back, or buttock that rapidly worsens, or is accompanied by signs of systemic distress such as rapid heart rate or dizziness, is a serious concern.
The inability to pass gas or stool, severe nausea, or persistent vomiting can signal a bowel obstruction or perforation. Buttock pain coupled with increasing localized tenderness, redness, or visible swelling in the perianal or gluteal area may indicate an external abscess or fistula formation that requires urgent intervention.