Hello
Thanks for the query.
Smelly farts are very common problem and generally due to the types of food we eat although fermentation by large number of microflora bacteria can also be responsible for this.
Flatulence-producing foods are typically high in certain polysaccharides. Those foods include beans, lentils, dairy products, onions, garlic,  turnips, radishes, sweet potatoes, potatoes, cashews,oats, wheat, and yeast in breads.
 Cauliflower, broccoli, cabbage, Brussels sprouts and other cruciferous vegetables that belong to the genus Brassica are commonly reputed to not only increase flatulence, but to increase the pungency of the flatus.
The smell in your fart is due to the presence of methane,hydrogen sulfide,dimethyl sulfide etc.

Remedies for you

Odor from flatulence, caused by the intestinal bacteria called microflora in the bowel, can be treated by taking bismuth subgallate, available over-the-counter as Devrom. 
Avoid above mentioned foods
Take plenty of water.
Avoid sweets and junk food.
Take some probiotics like yoghurt.
Chew and munch your food properly and avoid speaking during meals.

Some times giardiasis infection can also cause this problem and so you may get your stool tested for this,if you don't improve with above mentioned simple measures.

I hope to have answered your query however you may revert to me for any further query.
Best of luck
Thanks

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