Hello and welcome to e health forum.
Presence of bowel obstruction with chronic constipation along with indigestion and unhealthy dietary habits could be the cause of your bowel issues.
The presence of foul smell in the breath can be due to a number of conditions including - poor oral hygiene, tooth decay, cavities, lung infections (pneumonia, bronchiectasis), chronic sinus infections, atrophic rhinitis, gastro esophageal reflux disorder, zenker's diverticulum and malabsorption syndromes.
Presence of breath odor and signs such as fever, cough, or face pain with discharge from the nose could be due to a respiratory infection.
You may consult with a doctor for a examination and proper diagnosis of the underlying condtion, and get proper treatment.
In the mean time, follow proper dental hygiene, good healthy diet with lot of fibre.
Probiotic supplements and activated charcoal (Charcocaps) can help in reducing the odor in the flatus and also improve digestion.