Diverticulitis is a common digestive condition involving the inflammation or infection of small, bulging pouches, called diverticula, that form in the lining of the large intestine (colon). While primary symptoms center on the lower abdomen, the inflammatory process can cause discomfort that manifests in the testicles or groin area. This occurs because the nervous system routes pain signals from the deep abdominal organs.
How Inflammation Causes Referred Pain
The phenomenon of referred pain explains how an issue in one internal organ can be felt as pain in a distant, seemingly unrelated location. In the case of diverticulitis, the sigmoid colon, which is the most common site for inflamed diverticula, is situated deep within the pelvis and lower abdomen. This area is a dense crossroads for various nerve pathways that supply sensation to structures much further down the body.
The proximity of the inflamed colon to these pathways allows irritation to spread beyond the intestinal wall. Specifically, the genitofemoral nerve, which runs through the abdomen and supplies sensation to the skin of the groin and the scrotum, can become irritated by the surrounding inflammation. When the brain receives a pain signal from this nerve, it misinterprets the source because the nerve’s destination is the groin, not the colon. This misinterpretation is the reason the visceral pain from the intestine is perceived as somatic pain in the testicle.
Pain signals from the inflamed colon travel along shared nerve pathways that enter the spinal cord at similar levels as the nerves supplying the testicular region. Since the brain is accustomed to receiving signals from the skin and muscles, it localizes the sensation to the end of the nerve’s path. This results in pain that feels like it is coming directly from the testicle, even though the cause is irritation within the colon.
Specific Diverticulitis Complications Leading to Scrotal Pain
Beyond general inflammation causing referred pain, specific complications of diverticulitis can cause more direct and severe scrotal discomfort. A perforated diverticulum can lead to the formation of a pelvic abscess, which is a pocket of pus and infection outside the colon wall. This localized collection of infected fluid can exert physical pressure on adjacent structures and nerves, intensifying the pain felt in the groin and scrotum.
In rare instances, an abscess can track down the inguinal canal, the passage where the spermatic cord travels into the scrotum, leading to “acute scrotum.” This direct extension of infection is a severe complication causing intense, localized pain and swelling that mimics other serious testicular conditions. Such a presentation requires immediate medical intervention to drain the infection and treat the underlying diverticulitis.
Another severe complication is the development of a fistula, an abnormal connection between two organs. A colovesical fistula, a tract between the colon and the bladder, allows bacteria from the colon to enter the urinary tract. The resulting bladder infection can then ascend to the epididymis and testicle, causing epididymo-orchitis (inflammation of the epididymis and testicle). In these cases, the testicular pain is the result of a secondary bacterial infection that has spread from the colon.
When Testicle Pain Requires Immediate Medical Attention
Any sudden, severe pain in the testicle or scrotum must be treated as a medical emergency, even in the setting of a known diverticulitis diagnosis. Acute scrotal pain requires immediate evaluation to exclude time-sensitive conditions that can lead to the loss of the testicle if treatment is delayed. Testicular torsion, where the spermatic cord twists and cuts off blood supply, is one such emergency that presents with sudden, excruciating pain.
Infectious causes like epididymitis or orchitis, while also causing pain and swelling, develop more gradually over hours or days and may be accompanied by fever or burning during urination. Another possibility is an incarcerated hernia, which occurs when a portion of the intestine protrudes into the groin or scrotum and becomes trapped, causing a distinct, tender bulge. These conditions require different, urgent treatments than those for diverticulitis.
If the pain in the testicle is new, rapidly worsening, or accompanied by symptoms like fever, nausea, vomiting, or a visible scrotal bulge, seeking emergency medical care is paramount. While a physician may determine the pain is referred from the known diverticulitis, ruling out conditions like testicular torsion or a strangulated hernia must be the first priority.