Diverticulitis and an ovarian cyst can both cause pain in the lower abdomen, but they affect different organs. Diverticulitis is inflammation of small pouches in the colon and often comes with bowel changes or fever. An ovarian cyst is a fluid-filled sac on an ovary and may cause one-sided pelvic pain or no symptoms at all. Symptoms overlap, so the cause may require an exam and imaging tests.
What is the difference between diverticulitis and an ovarian cyst?
The main difference is where each condition develops. Diverticulitis affects the digestive system, specifically the large intestine, while an ovarian cyst develops in or on an ovary. Both can cause lower abdominal discomfort, which can make them difficult to distinguish based on pain alone.
Diverticulitis occurs when small pouches that form in the colon wall become inflamed. These pouches are called diverticula. An ovarian cyst is a sac containing fluid or other material that develops in or on an ovary. Many ovarian cysts cause no symptoms and disappear without treatment, while diverticulitis can require medical treatment to prevent or manage complications.
How do the symptoms compare?
What symptoms are associated with diverticulitis?
Diverticulitis commonly causes abdominal pain, particularly in the lower-left part of the abdomen. The discomfort may start suddenly or develop gradually. Other symptoms can involve the digestive system or occur when inflammation affects the body more broadly.
According to Mayo Clinic, symptoms associated with diverticulitis can include abdominal tenderness, nausea, fever, constipation, or diarrhea. These symptoms are not exclusive to diverticulitis, and their presence or absence cannot reliably establish the cause of abdominal pain.
- Pain or tenderness, often in the lower-left abdomen.
- Changes in bowel habits, including constipation or diarrhea.
- Fever or chills.
- Nausea or vomiting.
- Bloating or abdominal discomfort.
What symptoms are associated with an ovarian cyst?
Ovarian cysts frequently cause no noticeable symptoms and may be discovered during an ultrasound or pelvic examination performed for another reason. When a cyst causes symptoms, discomfort may be felt on one side of the lower abdomen or pelvis. Its location can depend on which ovary is affected.
The NHS explains that ovarian cysts can cause pelvic pain, pain during sex, bloating, a swollen abdomen, changes in menstrual bleeding, or a frequent need to urinate. A cyst that ruptures or causes the ovary to twist can produce sudden, intense pain that requires urgent assessment.
- A dull ache, pressure, or sharp pain on one side of the pelvis.
- A feeling of fullness or heaviness in the lower abdomen.
- Bloating or abdominal swelling.
- Pain during sexual activity.
- Changes in menstrual periods or more frequent urination.
Can both conditions cause pain in the same place?
Yes. Both conditions can cause pain in the lower abdomen, and pelvic organs and the bowel occupy nearby areas. Diverticulitis often causes pain on the lower-left side, while an ovarian cyst may cause pain on either side, depending on the affected ovary. These are typical patterns, not reliable ways to tell the conditions apart.
Digestive symptoms such as diarrhea or constipation may occur with diverticulitis, but bowel difficulties can also accompany a large ovarian cyst. Similarly, nausea can occur with either condition. The timing of symptoms, menstrual history, bowel changes, examination findings, and diagnostic tests help healthcare professionals distinguish between possible causes.
How do doctors determine which condition is causing the pain?
Healthcare professionals consider when the pain started, where it is located, whether it is constant or intermittent, and whether other symptoms have developed. They may ask about previous digestive problems, known ovarian cysts, menstrual changes, medications, and the possibility of pregnancy. An abdominal examination and, when appropriate, a pelvic examination can help guide further testing.
Tests used to investigate diverticulitis
Blood tests may help identify signs of inflammation or infection, while a urine test or pregnancy test may help assess other possible causes of lower abdominal pain. A computed tomography (CT) scan is commonly used when diverticulitis is suspected because it can show inflamed diverticula and possible complications, such as an abscess.
Mayo Clinic's diagnostic guidance for diverticulitis describes how examination findings and laboratory tests are considered alongside imaging. The choice of tests depends on the clinical situation and whether another abdominal or pelvic condition could explain the symptoms.
Tests used to investigate an ovarian cyst
A pelvic ultrasound is a key test for identifying an ovarian cyst. It can show the cyst's location, size, and appearance, including whether it is mainly fluid-filled or contains solid areas. An ultrasound may be performed through the abdomen or with a probe placed inside the vagina, depending on the circumstances.
According to Mayo Clinic's ovarian cyst diagnostic guidance, healthcare professionals may also use a pregnancy test, blood tests, or other investigations when indicated. Follow-up imaging can help determine whether a cyst changes over time. The test results are interpreted alongside symptoms, age, menopausal status, and medical history.
How does treatment differ?
Treatment for diverticulitis
Treatment depends on the nature of the inflammation, the person's overall health, and whether complications are present. Some uncomplicated cases can be managed at home with guidance on temporary dietary changes, fluids, rest, and symptom relief. Antibiotics may be prescribed when appropriate, but they are not necessary for every uncomplicated case.
More complicated diverticulitis may require hospital treatment, intravenous antibiotics, drainage of an abscess, or surgery. Severe or worsening abdominal pain, persistent fever, repeated vomiting, or signs of complications warrant prompt medical assessment rather than relying on home treatment.
Treatment for an ovarian cyst
Treatment depends on the cyst's appearance, size, symptoms, and the person's age and menopausal status. Many cysts disappear without treatment, so a healthcare professional may recommend observation and repeat ultrasound examinations. Monitoring helps determine whether the cyst is shrinking, remaining stable, or changing in a way that requires further investigation.
Surgery may be considered if a cyst is large, persistent, painful, growing, or concerning on imaging. Emergency treatment may be necessary if a cyst ruptures and causes significant bleeding or if the ovary twists and its blood supply is threatened. When surgery is planned, the healthcare team considers the findings and, when possible, aims to preserve ovarian function.
When should lower abdominal or pelvic pain be assessed urgently?
Sudden, intense abdominal or pelvic pain needs urgent medical assessment, particularly when it occurs with nausea, vomiting, fever, dizziness, or fainting. These symptoms can occur with complications of diverticulitis or an ovarian cyst, as well as with other conditions that need prompt treatment.
If pregnancy is possible, lower abdominal pain on one side, especially when accompanied by vaginal bleeding or shoulder-tip pain, also requires prompt medical evaluation. An ectopic pregnancy can cause similar symptoms and may become life-threatening if it ruptures. The NHS guidance on ectopic pregnancy explains when these symptoms require urgent assessment. Do not wait for symptoms to become more intense before seeking help.
Arrange medical evaluation for persistent, unexplained, or worsening abdominal pain, even when it is not sudden. The same applies to recurring pelvic discomfort, unusual menstrual changes, or new bowel symptoms. The appropriate next step depends on the symptoms and examination findings, rather than on the location of pain alone.
Does age affect the likelihood of either condition?
Age can influence how healthcare professionals evaluate these conditions. Diverticular disease becomes more common with increasing age, and diverticulitis is often considered when an older adult develops new lower abdominal pain. However, it can also occur in younger adults.
Ovarian cysts can occur during the reproductive years and after menopause. Functional cysts related to the menstrual cycle are common before menopause, and many resolve naturally. After menopause, a newly identified ovarian cyst deserves careful assessment because the possibility of ovarian cancer is greater than it is before menopause. The cyst's appearance, symptoms, and other clinical findings guide further investigation.
What is the most important difference to remember?
Diverticulitis affects the colon and often occurs with lower abdominal pain and changes in bowel habits. An ovarian cyst affects an ovary and may cause one-sided pelvic pain, pressure, bloating, or no symptoms. Although these patterns can help guide an initial assessment, neither condition can be reliably identified from symptoms alone. Medical examination and appropriate testing are the most useful ways to determine the cause and select suitable treatment.