Colostomy Odor & Gas: 8 Practical Solutions That Work

“I’m afraid I’ll smell in public places...”

This is perhaps the most psychologically burdensome issue after a colostomy. According to a systematic review by Vonk-Klaassen et al. (2016) ^[1] , odor and flatulence are reported as the #1 psychosocial problem by colostomy patients — even surpassing leakage. Many avoid social events, work, and sexual relationships out of fear.

The good news: there are specific solutions . In this guide we analyze 8 practical interventions that work — from the B Braun Flexima activated carbon filter to dietary adjustments.

Why does the odor occur?

The odor in colostomy bags comes from:

• Volatile organic compounds (VOCs) — indole, skatole, hydrogen sulfide, methyl mercaptan ^[2]
• Bacterial fermentation in the colon — the microflora produces gases when breaking down food
• Stool accumulation in the bag — the longer it is left, the more intense the odor odor
• Poor quality plastic — cheap bags let the odor permeate the material

Gas (flatulence) comes from:

• Swallowing air while chewing/drinking (aerophagia)
• Bacterial fermentation of indigestible carbohydrates (FODMAPs)
• Carbonated drinks

🎯 The 8 Practical Solutions

1. Activated Carbon Filter (Standard on Flexima)

The activated carbon filter is the No. 1 technological solution. It works as follows:

• Allows gases to escape from the bag — prevents “bloating”/ballooning
• Activated carbon absorbs volatile odor compounds before they reach the air
• Keeps the bag discreet in social situations

✅ All B Braun Flexima Colo bags (Active, Flat, 3S, Convex, Flat Drainable) have a built-in activated carbon filter as STANDARD — not as an extra. If your current bag does not have a filter, this is the most immediate improvement you can make today ^[3] .

2. Empty/change bag more frequently

The longer stool remains in the bag, the stronger the odor becomes due to continued bacterial activity. Practical:

• Drainable bag: Empty when 1/3 full — no more
• Closed bag: Change every 24 hours or when 50% full
• Before social events: Always empty/change 30 minutes before

3. Dietary Adjustments

According to the guidelines of UOAA ^[4] :

❌ Foods that increase odor	⚠️ Foods that cause gas	✅ Foods that reduce odor
Asparagus	Beans, chickpeas, lentils	Yogurt (probiotics)
Eggs, fish	Cabbage, broccoli, cauliflower	Cranberry juice
Garlic, onion	Carbonated drinks, beer	Parsley, butter
Hard cheese	Chewing gum (air swallowing)	Fresh milk cheesecake
Coffee (limitation)	Apples, pears (fructose)	Lemon, chamomile

Tip: Try keeping a food diary for 2 weeks — note what you eat and when the smell occurs. This will help you identify your own profile.

4. Probiotics & yogurt

Probiotics (Lactobacillus, Bifidobacterium) improve intestinal flora and reduce malodorous fermentation byproducts ^[5] .

• Natural yogurt with live cultures — 1-2 times a day
• Kefir — alternative with higher bacterial diversity
• Probiotic supplements (discuss with doctor)
• Fermented foods: sauerkraut, kimchi, miso (in moderation)

5. Discreet beige midi cover (Flexima)

In addition to the activated carbon filter, the design of the bag plays a role. Flexima bags have:

• Discreet beige midi cover — invisible under regular clothes
• Soft fabric backing — breathable, anti-perspirant
• Multi-layer film — prevents odor diffusion through the plastic

These details reduce the psychological burden and increase self-confidence.

6. Deodorant Drops / Tablets (when needed)

In persistent cases or for extra peace of mind, you can use:

• Deodorant drops: Drops placed in the pouch after changing
• Pouch deodorant tablets: Tablets that dissolve in the pouch
• Air freshener spray for the ballad in the bathroom after emptying

These are partially covered by EOPYY as part of “irritation treatment products” (Table 11, A/A 2) ^[6] .

7. Correct technique when changing/emptying

• Emptying into the toilet with a low opening — not from above (air + odor circulates)
• Cleaning the outlet of the tap with toilet paper or wipes after emptying
• Toilet closed during use
• Air freshener or candle in the bathroom
• Do not fill the bag with water for flushing — unnecessary and creates humidity in the filter that makes it useless

8. Manage gas by the way you eat

• Eat slowly with your mouth closed — less air swallowed
• Avoid chewing gum and candy (increase aerophagia)
• No soda or beer
• No cigarettes (swallow air)
• Simethicone (anti-gas) — over-the-counter medication that reduces gas in the intestines. Discussion with a pharmacist.

🎯 Decision Tree: How to reduce odor today

Situation	Solution
Bag without activated carbon filter	Immediate change to Flexima (all models have filter standard)
Bag with filter but odor	More frequent change + food diary
Bag inflation due to gases	Check filter (is it getting wet?) + change diet
Strong odor suddenly	Leakage? Fungus? — skin check + doctor
Social anxiety about odor	Deodorant drops + adding Pouch covers + psychological support
Constant gas	Probiotics + simethicone + slow food + avoiding carbonated drinks

⚠️ When Odor Is a Sign of a Problem

Usually odor is manageable. But in some cases it is a sign of a medical problem ^[7] :

• 🚨 Sudden very strong odor + fever = possible gastrointestinal infection
• 🚨 “Fatty” odor (not normal stool) = possible small intestinal bacterial overgrowth (SIBO) or C. difficile
• 🚨 Odor around stoma (not inside the pouch) = stool leakage under the base = see leakage guide
• 🚨 Odor with blood in the stool = immediate contact with a doctor

Try Flexima with activated carbon filter for free

Related articles

• Pillar C: Complete Colostomy Guide
• Colostomy bag: which one to choose?
• Colostomy diet — 30 foods you need to know
• Bag leakage — 7 causes & solutions

📚 Bibliography / Scientific sources

1. Vonk-Klaassen SM et al. Ostomy-related problems and their impact on quality of life of colorectal cancer ostomates: a systematic review . Quality of Life Research , 2016. pubmed.ncbi.nlm.nih.gov
2. Jiang T, Suarez FL, Levitt MD. Gas production by feces of infants . Journal of Pediatric Gastroenterology and Nutrition . pubmed.ncbi.nlm.nih.gov
3. B Braun Flexima Active Colostomy Bag — Technical Specifications (Activated Carbon Filter) . B Braun Avitum. catalogs.bbraun.com
4. UOAA — United Ostomy Associations of America: Diet & Nutrition Guide for People with Ostomies . ostomy.org/diet-nutrition
5. Hill C et al. The International Scientific Association for Probiotics and Prebiotics consensus statement . Nature Reviews Gastroenterology & Hepatology . pubmed.ncbi.nlm.nih.gov
6. Government Gazette B' 5395/09-10-2025 — Table 11, No. 2 (Colostomy Materials) . National Printing House. eopyy.gov.gr
7. WOCN Society Clinical Practice Guideline for Management of the Adult Patient with a Fecal or Urinary Ostomy . Wound, Ostomy and Continence Nurses Society. wocn.org
8. Colwell JC, Pittman J. Ostomy Care and Management . Journal of Wound, Ostomy and Continence Nursing , 2017. pubmed.ncbi.nlm.nih.gov