Bloating after 45: what is behind it and what to check

Where gas and bloating come from

The NIDDK explains that most gas comes from two places: air you swallow, and bacteria in the large intestine breaking down carbohydrates your small intestine did not fully digest. Belching, bloating, a swollen belly and passing gas are all normal to a point.

Bloating becomes a problem when it is frequent, painful or changes how you eat and live. At that point, the question is whether there is more gas than usual, whether gas is moving through more slowly, or whether your gut has become more sensitive to normal amounts.

Why it can change after 45

• Perimenopause and menopause: fluctuating hormones affect fluid balance and gut motility, and many women notice cyclical bloating that changes as periods become irregular
• Constipation: slower transit lets more fermentation happen and traps gas
• New medications: iron, some blood pressure drugs, opioids, GLP-1 medications and others can slow the gut
• Diet changes: more fiber, sugar alcohols, protein bars or shakes can increase gas
• Less physical activity, which slows gut movement
• Conditions such as lactose intolerance, celiac disease or irritable bowel syndrome, which can appear or become noticeable at any age

Red flags that come before any stool test

See a clinician in person promptly if bloating comes with any of these:

• Unintended weight loss
• Blood in the stool or black, tarry stools
• A lasting change in bowel habits
• Persistent bloating with feeling full quickly, pelvic pain or urinary changes, which in women can be a sign of ovarian problems
• Vomiting, difficulty swallowing or iron-deficiency anemia
• A family history of colorectal, ovarian or stomach cancer

Keep up with colorectal screening

Average-risk adults are generally advised to start colorectal cancer screening at 45. The National Cancer Institute describes several screening options, including stool tests that look for hidden blood or DNA changes, and colonoscopy.

A microbiome or functional stool panel is not a cancer screening test and cannot replace one. If you are due for screening, that comes first.

Is it irritable bowel syndrome?

The NIDDK lists bloating among the common symptoms of IBS, along with abdominal pain linked to bowel movements, diarrhea, constipation or both, and a feeling of incomplete emptying. IBS is diagnosed by a pattern of symptoms over time after other causes are reasonably excluded. It can be painful but does not damage the digestive tract.

If your symptoms fit IBS, first-line steps such as dietary adjustments, managing constipation, regular activity and stress management often help more than extensive testing.

Simple steps to try first

• Keep a two-week food and symptom diary
• Eat more slowly, and cut back on carbonated drinks and chewing gum
• Increase fiber gradually rather than all at once
• Test a short break from dairy, or from sugar alcohols such as sorbitol, to see if symptoms change
• Treat constipation with fluids, fiber and movement
• Review new medications or supplements with your clinician

When the stool panel can add something

If red flags have been addressed and simple measures have not helped, a broader stool panel can give your clinician more information. The GI Effects + Microbiomix panel looks at markers of digestion and absorption, gut inflammation and the makeup of gut microbes. Results can point toward fat malabsorption, signs of inflammation that warrant a specialist, or patterns worth targeting with diet.

Be realistic about what it can show. An international consensus statement on microbiome testing, published in 2025, concluded that evidence for the clinical usefulness of microbiome testing is still limited. Many findings are associations, not diagnoses.

Preparing for a stool panel

If you and your clinician decide testing makes sense, preparation affects the results. Antibiotics, probiotics, antacids, laxatives and some supplements can change what the lab finds, so your instructions may ask you to pause certain products for a period before collection if it is safe to do so. Do not stop prescribed medications without checking first.

Collect during a typical stretch of eating rather than after an unusual meal or a trip, and note any recent illness. Write down your symptoms on collection day, too, because a single sample is a snapshot that your clinician will read against how you were feeling.

How HealifyMD approaches bloating

Your clinician starts with your history, red flags and screening status, suggests first steps and, if testing is reasonable, explains what the panel can and cannot tell you before you order it. If results suggest a condition that needs in-person care, you will be referred. The GI Effects + Microbiomix panel is $1,095 as a one-time test, confirmed after your eligibility review. Lab tests are priced separately from treatment, and there is no membership fee.