Bad smells in drains can have a wide range of causes. These include:
• Build-up of organic matter like food particles, grease, or hair
• Blockages leading to stagnant water in the pipes
• Bacterial growth in the drains
• Damaged or cracked pipes allowing sewer smells to escape
• Insufficient ventilation in the plumbing system
Professional drain inspection can help to identify the specific cause and follow an appropriate solution.