It is important to understand the symptoms of diverticulitis flare-up, because the treatment of diverticulitis depends on the severity of the symptoms. Severe symptoms may require hospitalization, while mild symptoms can be treated at home. Some signs and symptoms of acute diverticulitis flare-up may indicate the presence of potentially life-threatening complications, and would require immediate surgery.
In the last 15 years, I have treated thousands of people hospitalized with diverticulitis flare-up with different levels of severity. I have written this article based on my personal experience as well as a thorough review of relevant medical journals.
In this article, I will explain three different levels of symptoms of diverticulitis flare-up and what needs to be done at each level. Here are the three different severity levels:
- Mild diverticulitis flare-up that can be treated at home
- Moderate-to-severe diverticulitis flare-up that requires hospitalization
- Diverticulitis flare-up with life-threatening complications
Symptoms of mild diverticulitis flare-up
Diverticulitis flare-up is also called acute diverticulitis. If you had a previously diagnosed episode of acute diverticulitis, you may know you are having a mild flare-up just based on your symptoms. If you never had diverticulitis before and have some of the following symptoms, you need to call your doctor and get tested for possible mild acute diverticulitis. A CT scan of your belly is usually very accurate in telling if you have acute diverticulitis or not.

Here are the symptoms of mild diverticulitis flare-up:
- Cramp-like abdominal pain, usually located towards the left side
- Feeling of incomplete bowel movements associated with the pain
- Nausea, vomiting, and bloating with the abdominal pain
- Low-grade fever or chills
- Feeling of increased gas in the abdomen
After a proper diagnosis, mild diverticulitis flare-up can be treated at home. You may need to stick with a clear liquid diet after the diagnosis. Medically, a clear liquid diet means thin liquids that appear clear at room temperature. Examples include tea or coffee without milk, Jell-o, popsicles and cranberry or apple juice without pulp or solids. You may also take over-the-counter pain medications and prescription anti-nausea medications. Treating mild diverticulitis with antibiotics at home used be a standard practice in the past, but recent research suggests that antibiotics may not be very helpful. You need to work with your doctor and decide if antibiotics will help with your particular diverticulitis flare-up symptoms.
You can expect to see improvements in a few days with decreased pain. A regular follow up visit with colonoscopy may be necessary in order to look inside your colon. However, if your symptoms worsen, you need to call your doctor right away.
Symptoms of moderate-to-severe diverticulitis flare-up
Moderate-to-severe diverticulitis may need hospitalization. If you have any of these symptoms, you may need to get yourself evaluated in the ER for possible hospitalization.
Here are the symptoms of moderate-to-severe diverticulitis flare-up:
- Severe, sharp pain in the left lower abdomen
- Abdominal pain that gets worse when you touch or press your belly
- High fevers and chills associated with abdominal pain
- Feeling dizzy or lightheaded
- Getting dehydrated from too much vomiting
When hospitalized for severe acute diverticulitis, you will get IV fluids, pain medications, possibly IV antibiotics, and close monitoring of your labs and vital signs. You may not need surgery unless things worsen.
Symptoms of diverticulitis flare-up with life-threatening complications
Certain symptoms, when present, may signal the presence of severe complications that can be life-threatening. Here are some of those symptoms:
- Severe, sharp pain, spreading to the whole abdomen
- A very sensitive abdomen with severe pain when touching it
- Feeling like you are fainting
- Low blood pressure
- High fevers with chills
- Fast heart rate
- Breathing fast and shallow
If you were hospitalized with symptoms of moderate diverticulitis flare-up and develop these symptoms despite treatment, you may need another CT scan of your abdomen. A follow-up CT scan can identify most urgent complications.
The major life-threatening issues arise when your diverticulitis bursts open, releasing the contents of your colon into the sterile area of your abdomen. You need urgent surgery to treat this. This can lead to sepsis and death unless treated urgently. Read “low blood pressure and fever: think sepsis” if you would like to know more about sepsis.
The other less severe complication is the formation of abscesses. Abscesses form when the diverticulitis leaks more slowly, and the leakage is contained by surrounding tissue. Large abscesses can also lead to sepsis and need careful monitoring. Sometimes, abscesses can be drained by placing a small tube under an x-ray. However, you may need urgent open surgery if things are unstable.
In conclusion, the symptoms of diverticulitis flare-up depend on the severity level. It is important to know those symptoms and get appropriate level of care. Severe symptoms with life-threatening complications may need urgent surgery.
References:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3961523/