Is it permissible to use western style toilets?
All Praise is due to Allah Alone and peace and blessings be upon His Messenger, his family, and Companions.
It is permissible to use any toilets (Part No. 5; Page No. 87) but try to protect your bodies and clothes from Najasah (ritual impurity) when relieving yourselves. After finishing, you should follow the Islamic way either by performing Istijmar (cleansing the private parts with hard material after urination or defecation) or Istinja' (cleansing the private parts with water after urination or defecation) and it is better to do both. Istijmar becomes sufficient if it is done with a purified object - even if paper - provided that it is done three times or more, as the Prophet (peace be upon him) said:
Save yourselves from (being spoiled with) urine, for that is the main cause of punishment in the grave.
The Prophet (peace be upon him) also forbade Istijmar with less than three stones.
If three were not enough, more should be used, but it is better to use an odd number, as the Prophet (peace be upon him) said:
Anyone who performs Istijmar should do it with an odd number (of stones).
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.