Is it permissible to insert a finger into the anus to facilitate defecation in cases of constipation, and does this affect the fast, whether it be obligatory or supererogatory?

Scholars differ concerning the ruling on inserting a finger into the anus for a fasting person: some deem it to break the fast, while others deem it not to break the fast. The latter is the preponderant opinion chosen by Sheikh Al-Islam Ibn Taymiyyah and Sheikh Ibn Uthaymeen, because it does not carry the meaning of eating and drinking, and because the default is not to break the fast when in doubt. Nevertheless, one should avoid this act and maintain the sanctity of the private parts, and seek other medical treatments if there is an illness that necessitates it.