Abdominal Bloating: Symptoms, Causes and Treatment

This guide explains abdominal bloating symptoms, causes, treatment, and when to seek care.

Bloating is a feeling of fullness, pressure, or tightness in the belly ^2,5. Distension means a clear increase in the belly’s size ².

Bloating and abdominal distension often occur together ². However, either symptom can occur alone ².

Occasional symptoms may follow a meal ². Persistent abdominal bloating can disrupt daily life and reduce quality of life ^2,7.

A bloated stomach may feel full, hard, tight, or swollen ⁵. Discomfort can range from mild to intense ⁵.

Excess gas is one possible cause ⁵. However, some people feel bloated despite having a normal amount of intestinal gas ⁵.

Food, bowel habits, hormones, medicines, and gut sensitivity may play roles ^4,5,7. Abdominal muscle responses can also cause visible swelling.

Treatment depends on the cause and the person’s symptom pattern ². A personalized evaluation may help address bloating symptoms ^2,3.

Bloating describes a feeling inside the abdomen ^2,6. Another person may not see any change in size.

Abdominal distension is a visible increase in abdominal size or girth ². Some people have severe bloating without visible swelling ².

Others develop swelling from an unusual muscle response. The diaphragm moves down while the abdominal wall relaxes.

This response lets the abdomen push outward. It can occur without a large rise in intestinal gas.

Bloating may occur with these other digestive symptoms:

GERD means acid and stomach contents flow back toward the food pipe. The full name is gastroesophageal reflux disease.

A clear symptom record can help show useful patterns. Track these details before speaking with a healthcare professional:

Stress can make some gut-brain symptoms worse. It does not directly cause IBS.

Eating too much or too fast can lead to bloating ^4,5. Fast eating can also increase swallowed air ^4,6.

Swallowed air is a common cause of bloating ⁴. Carbonated drinks add gas and may trigger symptoms ^5,8.

Gut bacteria break down carbs that were not fully digested ⁵. This process is called fermentation and can produce intestinal gas ⁵.

Lactose is a sugar found in milk products ². Poor lactose digestion may cause bloating, gas, and loose stools ^2,4.

Some people also have trouble absorbing fructose ^4,5. Fructose is a sugar found in fruit and many sweet foods.

Sugar alcohols are sweeteners that the body may absorb poorly ². Examples include sorbitol and mannitol ².

These sweeteners can promote gas production ². They may be present in gum, diet drinks, and coffee sweeteners ².

Beans, lentils, onions, garlic, and some vegetables can produce gas ⁴. Personal reactions can vary, so food tracking may help find triggers ⁵.

Constipation can cause stool and gas to build up ^4,5. Treating constipation may ease bloating when both problems occur ^3,4.

Irritable bowel syndrome is often called IBS. It may cause cramps, pain, bloating, gas, constipation, or loose stools.

IBS affects how the gut moves and senses its contents. Gut nerves may react strongly to small amounts of gas or stool.

Functional dyspepsia can cause upper abdominal bloating ⁶. Symptoms may begin soon after eating ⁶.

GERD is another common cause of bloating ⁴. It may occur with heartburn or indigestion.

Some people have visceral hypersensitivity ^5,7. This term means normal gut feelings seem much stronger or more painful.

People with this sensitivity may have a normal amount of gas ^6,7. Yet they may still feel marked bloating or pain ^6,7.

An unusual muscle reflex can also cause abdominal distension. The diaphragm tightens while abdominal wall muscles relax.

Small intestinal bacterial overgrowth is called SIBO. It means too many bacteria are present in the small intestine.

SIBO may cause bloating, pain, nausea, loose stools, and weight loss. Poor nutrition can also occur.

Prior surgery and slow gut movement can raise the risk of SIBO. Testing is used for selected people with relevant risks.

Bloating can occur during menstrual periods and pregnancy ⁵. Hormone changes during perimenopause can also cause bloating ⁵.

Hormones can affect fluid buildup and the movement of food through the gut ⁵. These effects may change gas and bowel patterns ⁵.

Some medicines may cause a bloated stomach ^4,5. Acarbose is one example ⁴.

Products that contain lactulose or sorbitol may also cause bloating ⁴. Review new medicines and supplements with a healthcare professional.

Celiac disease damages the small intestine after exposure to gluten ². This damage can affect digestion and lead to bloating ².

Inflammatory bowel disease can cause bloating ⁵. It includes Crohn’s disease and ulcerative colitis ¹.

A bowel obstruction can stop food and waste from moving through the intestines ^1,5. Slow gut movement may also cause contents to build up ⁵.

Ascites means fluid has built up inside the abdomen. It can cause ongoing swelling ⁵.

Pancreatic insufficiency means the pancreas does not make enough digestive enzymes ^4,5. It is another possible cause of bloating ^4,5.

Some abdominal or pelvic tumors may cause bloating ^4,5. Warning signs make a focused medical check more important.

Mild bloating may improve with changes to eating habits ^4,5. Consider these steps when no warning signs are present:

Do not remove many foods without a clear reason. Strict exclusion diets lack support for routine use outside confirmed celiac disease ⁶.

Constipation treatment may provide gas and bloating relief ^3,4. The best choice depends on the bowel pattern and other symptoms.

Bran is a type of insoluble fiber ⁴. It may increase gas and bloating ⁴.

Psyllium is a form of soluble fiber ⁴. It is often easier to tolerate than bran ⁴.

Medicines for constipation may help when bloating occurs with constipation. A clinician can help choose care based on the symptoms.

Hard or incomplete bowel movements may involve the pelvic floor ^3,6. Pelvic-floor muscles help control the passage of stool.

A brief lactose restriction may help assess suspected lactose intolerance. A breath test is another option.

FODMAPs are carbs that can ferment and produce gas ⁴. Some people link these foods with bloating ⁴.

A low-FODMAP plan should have support from a digestive health dietitian. Dietitian guidance can reduce needless food limits.

Blood tests may help rule out celiac disease. A small bowel biopsy should confirm the disease after positive blood tests.

Treatment should match the suspected cause ^2,3. Options for selected cases include the following:

Talk with a healthcare professional before using medicine for abdominal symptoms ¹. This advice is important when the cause remains unclear.

AGA guidance advises against probiotics for treating bloating and distension. The guidance does not support routine probiotic use for these symptoms.

The medical visit starts with a health history and physical examination. The clinician may ask when abdominal pain occurs ^1,7.

Timing and links with meals can guide the next steps ^1,7. The clinician may ask whether symptoms come and go ^1,7.

Share details about these health factors:

The examination may check for swelling, pain, tenderness, or a rigid abdomen. A rectal examination may show signs of pelvic-floor problems ⁶.

Testing should focus on the most likely cause. Routine, wide testing is not needed for uncomplicated bloating ^3,6.

Celiac blood tests may be used when celiac disease is possible. Positive results should be confirmed with a small bowel biopsy.

Breath tests can check for problems absorbing some carbs. They may assess lactose or other suspected food sugars.

Breath tests may also assess SIBO in some at-risk people. Glucose and lactulose are two substances used for these tests.

Anorectal testing checks how the rectum and pelvic floor work. It may help when passing stool is hard or incomplete.

Imaging is mainly used for warning signs or an abnormal examination. It may also be used when symptoms have recently worsened.

Upper endoscopy follows the same focused approach. It is not routinely advised for uncomplicated bloating.

A stomach-emptying test checks how fast food leaves the stomach. It is not a routine bloating test.

The test may be considered when nausea and vomiting are present.

A digestive health dietitian can guide a low-FODMAP plan. Dietitian care is also advised for celiac disease.

A gastroenterology specialist may help when warning signs require focused tests. Such tests may include imaging or upper endoscopy.

Pelvic-floor testing can identify people who may benefit from biofeedback. Ongoing hard bowel movements may support this type of referral.

Some abdominal symptoms require care without delay. Follow the emergency direction linked to each warning sign:

Pain strength alone does not show how serious the cause is ¹. Gas may cause severe pain ¹.

Some dangerous conditions may cause only mild pain ¹. Consider the full symptom pattern instead of pain strength alone.

Persistent or worsening bloating needs medical attention ⁵. Contact a healthcare professional for these concerns:

New symptoms in older adults may need more testing ⁶. Earlier assessment may also help people with alarm symptoms ⁶.

People with prior abdominal surgery may also need more testing ⁶. Surgery can raise the risk of SIBO and bowel problems.

Clear details can help guide focused testing. Bring this information to the medical visit:

For more information about rectal symptoms, see our guide to hemorrhoids.

Occasional bloating may improve with slower eating and smaller meals ^1,4,5. Regular movement and trigger management may also help ^1,2,5.

Treating constipation may ease bloating when both problems occur ^3,4. Persistent or worsening abdominal distension should receive medical evaluation ⁵.

Tests should match the symptoms, risks, and examination findings. Routine imaging or endoscopy is not advised for uncomplicated bloating.

Severe pain, bleeding, a rigid abdomen, or breathing trouble require emergency care now ¹. Vomiting with blocked stool also requires emergency care now ¹.