Diverticulosis occurs when small pouches, called diverticula, form in weak areas of the wall of the colon. Most people with diverticulosis have no symptoms. Diverticulitis occurs when one or more of these pouches become inflamed and can sometimes lead to serious complications.
Symptoms
Diverticulosis often causes no symptoms. When diverticular disease causes chronic symptoms, people may experience bloating, constipation, diarrhea, cramping or pain in the lower abdomen.
Diverticulitis more often causes new abdominal pain, commonly in the lower left abdomen. The pain may be severe and sudden or may become worse over several days. Fever, chills, nausea, vomiting, constipation or diarrhea may also occur.
Diagnosis
A healthcare professional will review symptoms and medical history and examine the abdomen. Blood tests, stool tests and imaging may be used. CT is commonly used when acute diverticulitis is suspected. Colonoscopy may be recommended in selected situations to evaluate the colon and rule out other conditions.
Treatment
Treatment depends on whether a person has uncomplicated diverticulosis, diverticulitis or a complication. Chronic symptoms may improve with an appropriate high-fiber diet or fiber supplement. Uncomplicated diverticulitis can sometimes be treated outside the hospital, and antibiotics are not required for every patient. Severe disease or complications generally require hospital treatment.
Abscess, obstruction, fistula, perforation, peritonitis or significant bleeding may require drainage, endoscopic treatment or surgery.
Diet and prevention
After recovery, a healthcare professional may recommend gradually increasing fiber through whole grains, vegetables, fruit, beans and other high-fiber foods. Current evidence does not support routinely avoiding nuts, seeds or popcorn simply because a person has diverticulosis.
Regular physical activity, avoiding smoking and maintaining a healthy weight may help reduce the risk of diverticulitis.
When to seek urgent medical care
Seek urgent medical assessment for severe or worsening abdominal pain, fever with abdominal pain, repeated vomiting, a markedly swollen abdomen, inability to pass stool or gas, or rectal bleeding. Heavy bleeding, fainting, confusion, severe weakness or signs of shock require emergency care.
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Sources
Last reviewed: 4 September 2026.
Medical disclaimer: This information is general and does not replace individual medical assessment, diagnosis or treatment.