Abdominal pain signals many different health issues, including kidney stones and diverticulitis, both known for causing severe discomfort. Both conditions can lead to a sudden, intense onset of pain requiring immediate medical help. Because symptoms can overlap, particularly in the abdomen, self-diagnosis is unreliable. Distinguishing between a urinary tract problem and a digestive system issue requires attention to the specific characteristics of the pain and accompanying symptoms.
Comparing Pain Location and Quality
The location and character of the pain are the most significant initial clues for differentiation. Kidney stone pain, known medically as renal colic, typically originates in the flank or the side of the back, just below the ribs. This intense pain often radiates downward toward the lower abdomen, groin, and sometimes the inner thigh as the stone travels through the ureter. The sensation is frequently described as “colicky,” meaning it comes in severe, sharp waves that build and then subside, but never fully disappear.
Diverticulitis pain is most often localized to the lower left quadrant of the abdomen because the diverticula—small pouches in the colon—are most common in the sigmoid colon. This pain tends to be persistent and steady, rather than waving, though it can involve cramping or tenderness upon palpation. While kidney stone pain causes patients to writhe and constantly shift position in search of relief, individuals with diverticulitis often find movement exacerbates their discomfort, preferring to remain still. Although diverticulitis typically presents on the left side, a kidney stone can also cause pain in the lower left abdomen.
Non-Pain Symptoms: Urinary vs. Gastrointestinal Clues
Beyond the pain itself, additional signs point toward either a urinary or a gastrointestinal issue. Kidney stones are part of the urinary system, causing symptoms related to urine production and passage. A person may experience hematuria, which is blood in the urine that can make it appear pink, red, or brown. The stone can also cause a persistent, urgent need to urinate, or dysuria (pain or a burning sensation during urination), as the body tries to flush out the obstruction.
Diverticulitis, an inflammation of the colon, produces symptoms associated with the digestive tract and a systemic inflammatory response. Since it involves infection, fever and chills are common non-pain symptoms. Gastrointestinal distress often manifests as nausea and vomiting, which can become severe. Significant changes in bowel habits, such as new-onset constipation or, less commonly, diarrhea, are frequently associated with the inflammation.
The Definitive Medical Diagnosis
Because overlapping pain locations make self-diagnosis unreliable, medical professionals rely on specific tests. For a suspected kidney stone, a urinalysis is a standard initial test to check for blood, signs of infection, or crystals. The definitive tool for locating the stone is typically a non-contrast computed tomography (CT) scan, which provides detailed images of the urinary tract and determines the stone’s size and location. Ultrasound is also an option, particularly for pregnant women or children, as it avoids radiation exposure.
Diagnosing diverticulitis involves blood tests to look for an elevated white blood cell count, a sign of infection and inflammation. The most accurate diagnostic imaging is a CT scan of the abdomen and pelvis, usually with contrast, which visualizes the inflamed, thickened walls of the colon. These imaging tests are crucial because they confirm the condition, help assess its severity, and rule out other possibilities. The combination of laboratory results and imaging provides the definitive answer, guiding appropriate treatment.
When to Seek Emergency Care
Regardless of which condition is suspected, certain symptoms require an immediate visit to the emergency room. Unrelenting, excruciating pain not relieved by over-the-counter medication requires professional intervention. A high fever, typically above 101.5°F, or the presence of chills, suggests a severe infection that could be spreading, potentially leading to sepsis.
Another serious warning sign is the inability to keep fluids down due to persistent nausea and vomiting, risking severe dehydration. For a suspected kidney stone, a complete inability to urinate is an emergency, as it indicates a total blockage of the urinary tract. Seeking immediate care for these red flags ensures timely treatment and prevents complications.