Bloating is a feeling of fullness or swelling in the abdomen, sometimes with discomfort or pain. Nearly everyone has it at some point. For many women it becomes a regular companion, worse by evening, worse after certain meals, or worse at certain points in the cycle.
Most of the time, bloating has an ordinary explanation. Sometimes it is the first sign of something that deserves a closer look. This article explains the difference, and the warning signs that mean it is time to be evaluated rather than to wait.
The common causes
Gas normally enters the digestive tract in two ways: when you swallow air, and when bacteria in the large intestine break down carbohydrates that were not fully digested. Eating quickly, chewing gum, and fizzy drinks add to the first. Certain carbohydrate-rich foods add to the second.
Federal health references list these common causes of bloating:
Swallowing air
Constipation
Gastroesophageal reflux disease, or GERD
Irritable bowel syndrome
Lactose intolerance and trouble digesting other foods
Overeating
Small intestinal bacterial overgrowth
Weight gain
Celiac disease can also cause gas symptoms, and testing for it is worth considering when bloating has no clear explanation.
The warning signs
Bloating on its own is common. Bloating that comes with other changes is different. Contact your clinician if bloating comes with any of the following:
Blood in the stool, or dark, tarry stools
Vomiting
Weight loss you did not intend
Abdominal pain
Diarrhea
Heartburn that is getting worse
Anemia, especially from low iron
Symptoms that wake you from sleep, such as diarrhea at night
Symptoms that begin for the first time at age 50 or older
A parent, sibling, or child with colorectal cancer, inflammatory bowel disease, or celiac disease
The National Institute of Diabetes and Digestive and Kidney Diseases adds a simpler rule: talk with your doctor if your symptoms change suddenly, or if gas symptoms are bothering you.
A warning sign specific to women
This one is easy to overlook, so it is worth stating clearly. Bloating, feeling full too quickly or having difficulty eating, pain or pressure in the pelvis, abdominal or back pain, and changes in bathroom habits, such as a more frequent or urgent need to urinate or constipation, can be symptoms of ovarian cancer.
The Centers for Disease Control and Prevention advises that if you have any of these for two weeks or longer, and they are not normal for you, you should see a doctor. Unusual vaginal bleeding should be seen right away. Most bloating is not cancer. The point is that persistent, new bloating in a woman should be evaluated rather than assumed to be digestive.
Family history and age
Your history changes how bloating should be read. If a parent, sibling, or child has had colorectal cancer or polyps, or if you have inflammatory bowel disease yourself, talk with your clinician, since earlier colorectal cancer screening may be advised. The U.S. Preventive Services Task Force now supports colorectal cancer screening beginning at 45.
Screening and symptoms are different things, though. Screening is for people without symptoms. If you have warning signs, they call for evaluation now, whatever your age.
Keeping a useful record
If your bloating does not fit the warning signs, a two-week record can still help you and your clinician. Note when it happens, what you ate in the hours before, your bowel habits, where you are in your cycle, and how much it affects your day. Patterns that are invisible day to day often become clear on paper.
The next article describes what a complete digestive workup includes, and why its order matters.
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This article is general education. It is not medical advice and does not replace care from your own clinician.
Sources
National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & Causes of Gas in the Digestive Tract. Last reviewed June 2021.
MedlinePlus Medical Encyclopedia, National Library of Medicine. Abdominal bloating. Reviewed April 6, 2020.
Arnold MJ. Diagnosis and Management of Celiac Disease: Guidelines From the American College of Gastroenterology. American Family Physician. 2024;109(1):92–93.
Centers for Disease Control and Prevention. Symptoms of Ovarian Cancer. February 26, 2025.
Centers for Disease Control and Prevention. 45 Is the New 50 for Colorectal Cancer Screening. Reviewed August 13, 2024.
Lacy BE, Pimentel M, Brenner DM, et al. ACG Clinical Guideline: Management of Irritable Bowel Syndrome. American Journal of Gastroenterology. 2021;116(1):17–44.
