7 most common causes
Stomach bloating is the sensation that your abdomen feels too full or swollen. Many people experience bloating, and it’s usually temporary.
It’s often caused by a buildup of gas or water. For example, you might have gas after eating a big meal and feel bloated. Or, women may retain water before and during their period, which can cause bloating.
But if you often feel bloated or have other symptoms, like abdominal pain and diarrhea, see your doctor or a gastroenterologist (digestive tract specialist). These are signs you may have a more serious condition such as irritable bowel syndrome, celiac disease, or liver disease.
There are a lot of surprising food groups that are high gas-producing foods, like certain fruits, which are usually considered healthy. Apples, pears, mangoes, watermelon, cherries, figs, and peaches are high-fructose fruits that can cause bloating. —Dr. Judy Kim
Bloating after eating
Some people feel bloated after eating. Certain foods are more likely to cause bloating and flatulence (gas). These are foods that are high in FODMAPs (fermentable oligosaccharides disaccharides monosaccharides and polyols), which can increase gas production. They include:
- Dairy products, such as milk, yogurt, and ice cream, especially for people with lactose intolerance.
- Fruits high in fructose, like apples, pears, mangoes, and watermelon.
- Wheat, barley, rye, garlic, and onion.
- Carbonated drinks.
Your doctor may recommend avoiding or limiting these foods to decrease bloating.
1. Irritable bowel syndrome (IBS)
Irritable bowel syndrome (IBS) is a chronic digestive system disorder that often causes bloating. It’s not clear what causes IBS. People who have it may have increased sensitivity to the normal movement and swelling that occurs in the intestines. There may be changes in the way the gut moves.
A study in the journal Gastroenterology found differences in the types of bacteria that live in the gut of people with IBS. Constipation caused by IBS can also increase the feeling of abdominal fullness and pressure.
People with IBS can have flare-ups that can be more intense and uncomfortable. Stress, diet, and other factors may cause these flare-ups.
While there is no cure for IBS, your doctor can treat it with dietary changes and medications, such as fiber supplements, antidiarrheals or laxatives, and certain types of antidepressants.
2. Small intestinal bowel overgrowth
- Abdominal pain
Small intestinal bowel overgrowth (SIBO) is when there’s an abnormal increase in the bacteria that live in your small intestine, such as E. coli or Klebsiella.
Several things can lead to SIBO. Surgery of the intestines that changes your anatomy can cause it. Decreased motility (movement) of the small intestine caused by IBS, diabetes, or opioid drugs can also cause SIBO. And people who have a weakened immune system (from conditions such as HIV) have a higher risk of SIBO.
SIBO can interfere with your body’s ability to absorb nutrients from your food, which can lead to vitamin deficiencies.
SIBO can be diagnosed using a non-invasive carbohydrate breath test. Your doctor may also recommend an endoscopy and colonoscopy to rule out other diseases.
Treatment may include dietary changes, nutritional supplements, and antibiotics to control bacterial overgrowth.
3. Lactose intolerance
Bloating is a common symptom of lactose intolerance. People with this condition have low levels of the enzyme lactase, which helps to absorb the lactose in dairy products. Lactose intolerance is very common, and most people develop it as they get older. It’s most common in people of African, Hispanic, and Asian descent.
Your doctor may recommend avoiding dairy (or eating small amounts of it), eating lactose-free dairy products, and taking lactase enzyme tablets or drops before you eat dairy.
Some people think that stomach bloating is caused by an increased volume of gas. It is more likely that people with bloating actually have an increased sensitivity to a normal volume of gas. —Dr. Kim
- Abdominal pain
- Hard or lumpy stools
- Straining to have bowel movements
- Feeling as if you can’t fully empty stool from your rectum
Constipation is when you have difficulty having a bowel movement or have fewer than three bowel movements per week. Constipation is very common
There are many causes of constipation, such as dietary issues (not getting enough fiber) or certain medications like opioid painkillers. It can be a symptom of other diseases, like diabetes or thyroid disease. Some people have constipation because of the slow transit of stool through their colon or if the muscles in the colon that push stool out are uncoordinated.
If you often have constipation, you should see your doctor. They may recommend increasing your fiber intake (or taking fiber supplements) and exercising regularly. Medications such as laxatives may be needed.
If these don’t help, your doctor can refer you to a gastroenterologist, who may perform tests such as colonoscopy to rule out any underlying diseases and prescribe other types of medications.
5. Celiac disease
- Abdominal pain
- Foul-smelling or floating stools
- Weight loss
Celiac disease is caused by an immune reaction to eating gluten, which is a protein found in wheat, barley, and rye. It affects the small intestines and can lead to nutrient and vitamin deficiencies.
It can also cause symptoms that are unrelated to the digestive system, such as skin rashes and anemia. Left untreated, it may cause bone weakening, infertility and miscarriage, and cancer.
Your doctor can diagnose celiac disease using blood testing that looks for antibodies in your blood. Your doctor may also recommend an endoscopy with a biopsy to check for celiac disease.
Treatments include following a gluten-free diet, taking vitamin and mineral supplements, and medication to control intestinal inflammation.
6. Liver disease (cirrhosis)
- Bloating or abdominal distention
- Jaundice (yellow skin or eyes)
- Fatigue or confusion
- Easy bruising
- Blood in stool or vomit (emergency)
Liver disease can be caused by many different issues, such as heavy alcohol use, viruses (hepatitis), fatty liver disease, medications, autoimmune disease, and inherited disorders.
When liver disease progresses, it can cause chronic damage and scarring of the liver, which leads to cirrhosis. People with cirrhosis can have bloating and their abdomens can stick out.
If you have serious symptoms, such as blood in stool or vomit, go to the ER. People with liver disease should see a liver specialist to treat the underlying causes of the disease.
To treat the fluid in the abdomen, your doctor may prescribe diuretics (“water pills”) to help decrease the amount of fluid in the body. They may recommend a procedure that uses a needle to remove fluid from the abdomen. Reducing dietary salt intake also helps decrease stomach bloating.
7. Ovarian cancer
- Abdominal or pelvic pain
- Nausea or vomiting
- Weight loss
Ovarian cancer is when a cancer develops in one or both ovaries. Women with ovarian cancer may have stomach bloating, abdominal or pelvic pain, or nausea and vomiting. They may also have a poor appetite and have lost weight without trying. Ovarian cancer can be genetic and can run in the family.
The risk of ovarian cancer increases with older age. Women who began their period at an early age or had menopause at a late age may have a slightly increased risk. Preventative screening is not recommended unless there is a family history or other risk factors. It may be diagnosed by imaging, such as pelvic ultrasound or CT scan.
Treatment depends on the type and stage of cancer, but it may include chemotherapy and surgery.
Other possible causes
A number of other conditions may cause stomach bloating:
- Bowel obstruction
- Colon cancer
When to call the doctor
See your doctor if you have any of the following:
- Persistent abdominal bloating
- Weight loss
- Chronic diarrhea
To help bloating caused by dietary factors, avoid or restrict those food groups. If you are constipated, increasing fiber in your diet or taking laxatives may help. Making sure that you stay hydrated (drink enough water) and active can also help your digestion. —Dr. Kim
Should I go to the ER for stomach bloating?
You should go to the ER if you have the following:
- Avoiding dietary triggers you may be sensitive to, such as dairy products, gluten, or gas-producing foods
- Lactase enzyme tablets or drops
- Fiber supplements
- Vitamin and mineral supplements
- Anti-diarrheal medication
- Drinking enough water to stay hydrated
- Exercising and avoiding being sedentary
Other treatment options
- Medications that relieve constipation, such as those that draw more water into your colon
- Medications that control intestinal inflammation
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