What is the ruling on Muslim patients using ostomy bags or medical devices that contain impure materials?

Summary

Medical devices such as ostomy bags that contain materials derived from pigs, other non-halal animals or halal animals not slaughtered are considered impure and may not be used by Muslim patients, unless the materials are verified to have undergone complete transformation (istihalah). Devices not confirmed as impure may be used, and if they are later found to be impure this is pardoned. Use is also permitted when the patient has no other choice. Obligatory prayers must still be performed according to ability, and prayers already performed need not be repeated if the impure material was used out of ignorance or lack of alternatives.

Written in our own words from the original fatwa — check the source before acting on it.