Most cases of diverticulitis are mild and can be treated at home with rest, dietary changes, and sometimes antibiotics. The approach depends entirely on severity: uncomplicated cases often resolve within a week or two, while complicated cases involving abscesses, perforations, or widespread infection may require hospitalization, drainage procedures, or surgery.
Mild Cases Don’t Always Need Antibiotics
For years, antibiotics were standard treatment for every diverticulitis flare. That’s changed. The American Gastroenterological Association now recommends that antibiotics be used selectively rather than routinely in otherwise healthy patients with mild, uncomplicated diverticulitis. If you’re generally healthy, have no immune system issues, and your symptoms are manageable, your doctor may recommend a watch-and-wait approach with rest and dietary changes alone.
Antibiotics are still recommended when certain red flags are present. These include existing health conditions or frailty, symptoms that aren’t improving or are getting worse, vomiting, or lab work showing elevated markers of infection (high white blood cell count or high C-reactive protein levels). Antibiotics are also advised when imaging shows a fluid collection near the inflamed area or a longer stretch of colon is involved. If you do need antibiotics, a typical outpatient course involves oral medications that target the types of bacteria found in the colon. The course generally lasts 7 to 10 days.
What to Eat During a Flare
During the first few days of an acute flare, your doctor may have you stick to clear liquids only: broth, plain gelatin, water, clear juices, and ice pops. This gives your colon a chance to rest and reduces irritation at the inflamed site. You shouldn’t stay on clear liquids for more than a few days unless specifically told otherwise.
As your pain starts to ease, you’ll gradually add low-fiber foods back in. Think white rice, plain pasta, eggs, well-cooked vegetables without skin, and small portions of lean protein. Aim for five to six small meals a day with about one to two ounces of protein at each, paired with another low-fiber food. This transitional phase matters because jumping straight to a full diet can retrigger symptoms.
Once the flare has fully resolved, your doctor will likely recommend slowly increasing your fiber intake over several weeks. A high-fiber diet is one of the most effective long-term strategies for reducing the chance of future flares, though adding too much fiber too quickly can cause bloating and gas.
Pain Relief: What’s Safe and What Isn’t
Managing pain during a diverticulitis flare requires some caution, because common painkillers can actually make things worse. NSAIDs like ibuprofen and naproxen weaken the protective lining of the colon in two ways: they reduce the natural compounds that shield the intestinal wall, and they dampen the body’s ability to contain small perforations. In studies of patients with perforated diverticular disease, NSAID use was found at roughly 10% compared to under 4% in control groups, a meaningful increase in risk.
Opioid painkillers carry their own problems. They increase pressure inside the colon, particularly in segments already affected by diverticula. That added pressure can worsen existing pouches or even contribute to perforation. For these reasons, acetaminophen (Tylenol) is generally the safest over-the-counter option for pain during a flare. Heat pads on the lower abdomen can also help. If your pain is severe enough that acetaminophen isn’t cutting it, that’s a sign you may need medical evaluation rather than a stronger painkiller.
When You Need to Be in the Hospital
Not everyone can ride out a flare at home. Hospital admission is typically needed when you can’t keep fluids down, your pain is severe and not responding to oral medications, you have signs of a systemic infection like high fever or a very elevated white blood cell count, or imaging reveals complications like an abscess or perforation. People with significant other health conditions or weakened immune systems are also more likely to need inpatient care.
In the hospital, treatment centers on IV antibiotics, IV fluids, and bowel rest (no eating). Most people improve within a few days and can transition to oral antibiotics and a gradual diet before going home.
How Abscesses Are Treated
An abscess, a walled-off pocket of infection, is one of the most common complications of diverticulitis. How it’s handled depends on its size. Abscesses smaller than 3 centimeters (about the size of a large grape) can often be treated with antibiotics alone, since they’re too small for a drainage procedure to be practical or safe.
Abscesses 3 centimeters or larger typically need to be drained. This is usually done with a needle guided by CT imaging, inserted through the skin into the abscess. The procedure avoids the need for surgery in most cases and, combined with antibiotics, allows the infection to clear. If the abscess is in a location where a needle can’t safely reach it, or if drainage fails, surgery becomes the next option.
When Surgery Is Necessary
Surgery is reserved for the most serious situations. Surgeons classify complicated diverticulitis into four stages based on severity. Stage I involves a small abscess right next to the inflamed colon. Stage II means the abscess has tracked farther away, into the pelvis or behind the abdominal organs. Stage III is purulent peritonitis, meaning pus has spilled freely into the abdominal cavity. Stage IV is fecal peritonitis, where intestinal contents have leaked into the abdomen. This is the most dangerous scenario.
For Stage I and II disease, drainage plus antibiotics often avoids surgery. Stage III can sometimes be managed with a less invasive approach: laparoscopic lavage, where a surgeon rinses the abdominal cavity through small incisions. Stages III and IV typically require removal of the affected segment of colon. In some cases, the surgeon can reconnect the remaining bowel immediately. In others, particularly in emergency situations with heavy contamination, a temporary colostomy is created, which is usually reversed in a later operation once healing is complete.
Surgery is also considered on a non-emergency basis for people who have repeated flares that significantly affect their quality of life, or who develop complications like fistulas (abnormal connections between the colon and other organs) or strictures (narrowing of the colon from scar tissue).
Follow-Up After a Flare
After your first episode of diverticulitis, your doctor will typically recommend a colonoscopy once the inflammation has fully settled, usually about six to eight weeks after the flare. The purpose isn’t just to check on the diverticula. It’s to rule out colorectal cancer, which can mimic diverticulitis on imaging. This is especially important if you haven’t had a recent colonoscopy or if your episode was particularly severe.
Long term, the focus shifts to prevention. Gradually building up to a high-fiber diet (fruits, vegetables, whole grains, legumes) is the most well-supported strategy. Regular physical activity and maintaining a healthy weight also lower recurrence risk. The old advice to avoid nuts, seeds, and popcorn has largely been abandoned, as there’s no evidence these foods trigger flares.