Gas with a colostomy or ileostomy usually comes from two sources: air you swallow and gas produced when bacteria ferment food in your gut. Here are the common culprits.

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Foods that commonly cause gas

• Beans, lentils, and peas, which contain hard-to-digest sugars that bacteria ferment

• Cruciferous vegetables: broccoli, cauliflower, cabbage, Brussels sprouts

• Onions, garlic, leeks, and other alliums

• Carbonated drinks, including soda, sparkling water, and beer

• Dairy, especially if you've become lactose intolerant (this can develop or worsen after bowel surgery)

• Sugar alcohols (sorbitol, mannitol, xylitol) found in sugar-free gum, candy, and "diet" products

• Eggs, fish, and some meats, which can add odor along with gas

• High-fat or very rich foods, which can slow digestion and increase fermentation

• Mushrooms, cucumbers, radishes, and corn

• Large amounts of fresh fruit or fruit juice, particularly apples, pears, and melons

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Behaviors that cause you to swallow more air

• Eating or drinking quickly

• Talking while eating

• Chewing gum or sucking on hard candy

• Drinking through straws

• Smoking or vaping

• Skipping meals, then eating a large meal at once

• Not chewing food thoroughly (poorly chewed food also ferments more)

• Anxiety, which often increases air swallowing

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Things specific to ostomy situations

• Ileostomy: Gas is often less than with a colostomy because less of the colon (where most fermentation occurs) remains. Gas that does occur can come from swallowed air or from the high-fiber foods that can also cause blockages. Chew these very well.

• Colostomy: More of the colon is intact, so fermentation is more likely, especially with the foods listed above.

• Small intestinal bacterial overgrowth (SIBO) can occur after bowel surgery and cause excess gas.

• Medications and supplements such as iron, some antibiotics, and fiber supplements can contribute.

• Constipation or partial blockage can trap gas and cause bloating and cramping.

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Practical tips

• Introduce suspect foods one at a time and keep a food diary to find your personal triggers. Tolerance varies a lot from person to person.

• Eat smaller, more frequent meals and chew slowly.

• Some people find yogurt, buttermilk, or parsley help reduce gas and odor, though evidence is mostly anecdotal.

• Ostomy pouches with charcoal filters let gas vent, and deodorizing drops can help with odor.

• Simethicone and activated charcoal are commonly used, but check with your ostomy nurse or doctor first.

 

When to get it checked
Contact your doctor or ostomy nurse if gas comes with severe pain or cramping, a swollen belly, little or no output from the stoma, nausea or vomiting, or a stoma that looks dark, purple, or very pale. Those can signal a blockage or other complication that needs prompt attention.

An ostomy specialist nurse and a registered dietitian are great resources for personalized help, since the best approach depends on the type of ostomy and how much bowel was affected.

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