Is It IBS or Ovarian Cancer?

March is Ovarian Cancer Awareness Month and although these two conditions share similar symptoms, subtle differences can help determine if it’s time to see a healthcare provider and possibly save a life.

Overlapping symptoms often occur in many health conditions, and it's difficult to rush to the hospital for any slight inconvenience. For example, the common cold can sometimes cause symptoms similar to influenza. However, it’s critical to figure out what’s causing the symptoms to ensure prompt and appropriate treatment. Because ovarian cancer needs immediate attention, it’s best to err on the side of caution and visit a healthcare provider for a diagnosis.

Early and accurate diagnosis is important to ensure a better outcome. But when another condition like irritable bowel syndrome also presents symptoms similar to ovarian cancer, how can you tell the difference?

What is IBS?

Irritable Bowel Syndrome (IBS) is a chronic and functional gastrointestinal disorder that affects the large intestine. It is a common condition that affects about 10% to 15% of people in the United States — with symptoms that can vary in severity and frequency from person to person.

The exact cause of IBS is not fully understood. Still, it’s believed to be related to how the gut muscles contract, leading to changes in bowel movement patterns and abdominal pain, bloating, and discomfort. In addition, specific triggers, such as stress, certain foods, or hormonal changes, can also worsen symptoms.

IBS is typically diagnosed based on specific symptoms, including abdominal pain or discomfort, bloating, and changes in bowel habits such as diarrhea, constipation, or a combination of both.

What is ovarian cancer?

Ovarian cancer, the seventh most common cancer for women, is a type of cancer that begins in the ovaries. It can occur in different ovary parts, including the germ, stromal, and epithelial cells.

Statistics from 2023 estimate that 19,710 women will be diagnosed with ovarian cancer and 13,270 will die from it, according to the American Cancer Society.

Known as the "silent killer" due to its lack of symptoms and going undetected for years, the cancer typically develops in older white women, with half being 63 years old or older. Early detection of ovarian cancer can be challenging because it might not cause specific symptoms until it’s more advanced. However, some symptoms associated with ovarian cancer include bloating, abdominal pain, difficulty eating or feeling full quickly, and changes in bowel or bladder habits.

Can symptoms of IBS and ovarian cancer overlap?

Alex Polyakov, MBBS, Associate Professor and Gynecologist at the University of Melbourne, tells Healthnews, "irritable bowel syndrome (IBS) and ovarian cancer are two distinct medical conditions that may present with some overlapping symptoms."

"IBS is a functional gastrointestinal disorder characterized by recurrent abdominal pain or discomfort, bloating, and changes in bowel habits," he explains. "The symptoms of IBS are typically chronic, but they do not cause any structural damage to the digestive system."

Alan Lindemann, M.D., an obstetrician and maternal mortality expert, tells Healthnews that ovarian cancer symptoms are similar to IBS symptoms in even moderately advanced stages.

"On the other hand, ovarian cancer is a serious disease that develops in the ovaries, which are part of the female reproductive system," Lindemann continues. "In some cases, ovarian cancer may cause gastrointestinal symptoms similar to those seen in IBS, including abdominal discomfort and bloating."

"However, the underlying causes of these symptoms differ in each condition, and ovarian cancer requires prompt medical attention," Polyakov adds.

The British Society of Gastroenterology suggests that persistent abdominal bloating should be addressed by a doctor as patients confusing ovarian cancer as IBS can be life threatening.

How to tell the difference between IBS and ovarian cancer

Polyakov says that although IBS and ovarian cancer may share some symptoms, key differences can help distinguish between the two conditions.

"In ovarian cancer, a person may experience pelvic pain or pressure, persistent abdominal swelling or bloating, and difficulty eating or feeling full quickly," he explains. "These symptoms are typically more severe than those seen in IBS and may be accompanied by other symptoms, such as urinary problems and changes in menstrual cycles."

"In contrast, the symptoms of IBS are typically less severe […]. The symptoms of IBS may also vary in intensity over time and may be triggered by stress or certain foods," Polyakov says.

Lindemann says IBS pain is "more likely to be generalized, all over your abdomen or anywhere, while ovarian cancer is more likely to be contained in the lower abdomen, initially on one side or the other. The bloating of IBS will come and go, but the mass of ovarian cancer will not go away."

"Ovarian cancer is often associated with ascites, a fluid collection in the abdomen which causes the abdomen to enlarge," he adds.

Ovarian cancer symptoms are more frequent than IBS as well. Approximately 72% of women had at least two symptoms — the most common being back pain and fatigue — 20 to 30 times a month, according to a 2004 JAMA study. Bloating, abdominal size and urinary symptoms occurred in 43% of ovarian cancer patients.

What to do if you suspect IBS or ovarian cancer

Polyakov says it’s critical to seek medical attention if you’re experiencing persistent or severe symptoms that interfere with daily activities or quality of life.

"In general, any unexplained change in bowel habits, abdominal pain or discomfort, or bloating that lasts for more than a few weeks should be evaluated by a healthcare provider."

- Alex Polyakov

Serious symptoms are weight loss, blood in stool or urine, fever, or vomiting.

"Early detection of ovarian cancer is crucial," notes Polyakov. "The disease can be challenging to diagnose in its early stages, but that is when it is most likely to be treated successfully. A doctor may perform a physical exam, imaging tests, or blood tests to help diagnose the underlying cause of symptoms and develop an appropriate treatment plan."

Lindemann says that although abdominal pain, stool changes, and bloating are common symptoms for all stages of ovarian cancer and IBS, these symptoms are also very common in many other conditions.

"In a nutshell, here is the diagnostic dilemma," he explains. "While 100 percent of ovarian cancers will eventually have abdominal pain, bloating, and stool changes, less than one percent of patients with those symptoms will have ovarian cancer."

He suggests that women should be aware of new or worsening symptoms. If you notice any changes, "then find a doctor who will listen to you, and based on a careful history and physical, order the correct tests," Lindemann says. "That’s your best chance for finding ovarian cancer early enough to treat [it] successfully."