Diverticulitis is a common but often misunderstood digestive condition that can range from mild discomfort to serious illness requiring surgery. It develops from diverticulosis—a condition in which small, balloon-like pouches form in the wall of the colon. While diverticulosis itself is typically harmless and often goes unnoticed, diverticulitis occurs when those pouches become inflamed or infected, leading to symptoms that can significantly impact daily life.
If the small pouches, known as diverticula, do become inflamed, patients can experience pain, fever, nausea and changes to their stool. While mild cases can be treated with rest, lifestyle changes and potentially antibiotics, more severe cases might require hospitalization and surgery. For many patients, the condition raises questions about causes, treatment options and long-term risks.
The AMA’s What Doctors Want Patients to Know™ series gives physicians a platform to share what they want patients to understand about today’s healthcare headlines.
In this installment, Benjamin Kuritzkes, MD, a colon and rectal surgeon with Atlantic Health and section chief of colorectal surgery at Atlantic Health Overlook Medical Center, took time to discuss what patients should know about diverticulitis.
Atlantic Health is part of the AMA Health System Member Program, which provides enterprise solutions to equip leadership, physicians and care teams with resources to help drive the future of medicine.
Diverticulitis is an inflammation of the colon
“Colonic diverticulosis is herniation of the inner layer of the colon wall through its outer layers, causing the formation of balloon-like sacs along the wall of the colon. Diverticulosis in and of itself is a common and asymptomatic condition,” said Dr. Kuritzkes, noting that “colonic diverticulitis is inflammation of the colon, within and adjacent to an area of diverticulosis.”
“Although about 70% of adults 80 years old will have findings of diverticulosis in their colon, less than 5% of people with diverticulosis develop diverticulitis,” he said. “Most of the time, diverticulitis involves the sigmoid colon, but it can affect any portion of the colon that has diverticulosis.”
Symptoms of diverticulitis vary
“Common symptoms of diverticulitis include abdominal pain in the left lower abdomen, changes in bowel function—such as diarrhea or constipation—nausea, and sometimes fever,” said Dr. Kuritzkes, noting that “many patients report knowing that an attack is coming.”
“They might feel a cramp or an ache in the left lower quadrant, followed by low-grade fevers or chills, and reduced appetite,” he explained.
The cause of diverticulitis is not understood
“The cause of diverticulitis is incompletely understood,” Dr. Kuritzkes said. “Currently, we believe that this is both an inflammatory and an infectious condition.”
“Contributing factors may include a diet rich in fat and red meat and low in fiber, smoking, reduced physical activity and obesity,” he said. “Other associated factors include male sex, increasing age and possibly the use of non-steroidal anti-inflammatory drugs” (NSAIDs).
Diverticulitis is a condition with a broad range
“I generally think of diverticulitis as a spectrum, ranging from relatively mild, uncomplicated diverticulitis to severe, complicated disease,” said Dr. Kuritzkes. “In uncomplicated diverticulitis, the colon is inflamed but is often able to ‘repair’ itself. Most of these cases resolve with medical treatment.”
“Complicated disease—marked by perforation of the colon, abscess, stricture [narrowing] or fistula—is inherently more severe and is generally an indication for operative management,” he said. “Patients with ‘smoldering’ diverticulitis fit somewhere in between uncomplicated and complicated disease.”
“These patients have signs and symptoms of uncomplicated disease that don’t resolve,” said Dr. Kuritzkes. “Often these patients ‘never feel 100% better’ in between flares of uncomplicated disease and may benefit from operative management as well.”
These are signs of more complicated diverticulitis
“Signs of complicated diverticulitis depend on the complication,” Dr. Kuritzkes said. “Patients with colonic perforation or abscess may have severe abdominal pain and high fever. Oftentimes symptoms are severe enough to bring patients to the emergency department.
“Fistulas may cause urinary tract infections or, rarely, drainage from the vagina,” he added. “Stricture can cause increasing difficulty with bowel movements, with narrow caliber stools.”
Diverticulitis is diagnosed with a CT scan
“Diverticulitis is often first diagnosed on CT scan. This is the best initial test to evaluate a patient with suspected diverticulitis,” Dr. Kuritzkes said. “It typically appears as inflammation of the colon, alongside findings of diverticulosis.”
“However, a CT scan alone isn’t enough. Other types of infectious and inflammatory colitis, and even colon cancer, can mimic the appearance of diverticulitis on a CT scan,” he said. “Therefore, patients should generally undergo a colonoscopy after their symptoms have resolved to confirm the diagnosis, if they haven’t had a recent colonoscopy.”
Some cases of diverticulitis improve without antibiotics
“Many cases of mild, uncomplicated diverticulitis resolve with non-operative management,” Dr. Kuritzkes said. “There are many studies now that demonstrate that antibiotics are not required, and that often patients will improve with bowel rest—a clear liquid diet—alone.”
“Antibiotics may be appropriate for patients with other medical conditions, signs of severe infection or a history of immunosuppression,” he said. “At-home management may be a reasonable strategy for patients who have an established diagnosis of diverticulitis, and who can follow up with their primary care doctor or colorectal surgeon.”
“Patients experiencing symptoms for the first time, or those with severe symptoms—severe pain, high fever or inability to drink enough liquid to stay hydrated—should seek medical attention,” Dr. Kuritzkes emphasized.
Surgery may be needed for complicated diverticulitis
“Medical treatments for diverticulitis often include bowel rest, with or without antibiotics,” said Dr. Kuritzkes. “Surgical resection of the affected portion of colon—most commonly the sigmoid colon—is the definitive treatment for diverticulitis.”
“In general, I recommend surgery for patients with complicated diverticulitis, or those with recurrent, uncomplicated or smoldering diverticulitis when the burden of symptoms outweighs the risk of surgery,” he said. “It is important to understand that although surgery for diverticulitis is major surgery, it can significantly improve patients’ lives. The risk of recurrent diverticulitis after surgery is very low, generally cited as less than 2%.”
Be mindful of NSAID use
“There is an association between NSAID use and diverticulitis,” said Dr. Kuritzkes. “Patients with a history of diverticulitis should probably avoid excessive use of NSAIDs—such as ibuprofen.”
This is because “regular use has been associated with increased risk of diverticulitis,” he said. “However, limited use is probably safe.”
Lifestyle choices make an impact on diverticulitis
“There are no treatments that have been shown to prevent the risk of developing diverticulitis,” said Dr. Kuritzkes. “However, patients who eat a healthy diet rich in fiber and maintain an active lifestyle, while avoiding smoking or excessive alcohol consumption, are at the lowest risk of developing diverticulitis.”
“Patients can reduce their risk of diverticulitis by reducing red meat intake, stopping smoking and losing weight,” he said, noting “there are no medications that have been proven to reduce risk of diverticulitis.”
“However, medications including mesalamine and rifaximin may improve chronic symptoms,” Dr. Kuritzkes said. “Probiotics have not been shown conclusively to reduce the risk of diverticulitis.”
Most patients don’t need a colostomy
“Many people dread the idea of having diverticulitis surgery because of its association with colostomy, ‘the bag,’” said Dr. Kuritzkes. “Colostomy can be a life-saving treatment in patients with severe diverticular disease requiring emergency surgery, when it may not be safe to reconnect the colon during surgery.”
“The vast majority of patients undergoing planned, elective surgery for diverticulitis do not require creation of a colostomy,” he said.
