Brief Answer:
I would like to make her bowel pattern more regular

Detailed Answer:
Hello

Thanks for the query

Constipation itself is a major cause of excessive and stinking flatulence.
The smell in gas is mainly due to sulphur compounds.
As you mentioned that your daughter is suffering from chronic constipation I would like to know whether she has been worked up for celiac disease or not.
Constipation gives more time to bacteria to act on retained food in intestine and thus more of gases are produced.
Avoiding particular items in diet and normal bowel movements helps in relieving excessive flatulence.
I would suggest you to avoid cabbage, cauliflower, broccoli, beans, milk, cheezen, yoghurt, bread and gluten containing cereal like wheat in the food to avoid excess gas formation.
Give her fiber rich diet specially fruits with plenty of water to make the bowel regular.
Doing aerobic exercise also helps.
If she has not been worked up for celiac disease I would like to get it done as gluten sensitivity can also cause excessive fart.
I would like to give carminative to ease the stinky fart.
I hope this helps.
Please do ask if you have any more query.
Regards

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Brief Answer:
You can give Exlax

Detailed Answer:
Thanks for the follow up

I have searched the OTC medicine which can be given for relief of constipation.
You can give Exlax a laxative containing senna in a dose of 5 ml thrice a day to clear the bowel.
Relieving constipation will also provide relief in stinky fart.
Apart from this give plenty of fluids and fiber rich diet.Consult your pediatrician to know about the celiac test.

Regards

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