RNS can and does kill, don't let your tortoise become a victim. Inspect nostrils daily if possible and get expert help fast if you spot any nasal discharge. If this does not work, consult your veterinarian for advice. This condition is almost invariably the result of poor dietary management. Increase fibre intake substantially.
Laxatives commonly used are liquid parafin and lactulose.
Dandelion root added to feed will often work here too. Overfeeding of fruit is a common cause. Use drugs only if an infection is present, consult your veterinarian. Any foul smelling diarrhoea should be reported to your vet without delay. A fecal sample should be checked for evidence of worms or flagellate organisms.