Colostomia

Colostomia is a boss introduced in The Binding of Isaac: Repentance and can appear in.

Phase 1
Colostomia alternates between the following attacks:
 * Hops in place and then slides toward Isaac in the closest cardinal direction, firing projectiles in both perpendicular directions as she moves and leaving trails of explosive gas.
 * The slide can be at a slight angle if Isaac isn't perfectly aligned with it.
 * Colostomia continuously performs this attack until ~40% of the room is covered in explosive gas.
 * Launches a Bomb towards Isaac that ignites any gas clouds its explosion hits, causing a chain of explosions.
 * This is always her first attack upon spawning.
 * Unlike Isaac's Butt Bombs, these do not fog the room.

Phase 2
After dropping to half health, the bag containing Colostomia explodes, creating explosive clouds and leaving her adhering to the floor.
 * Jumps to another nearby location, firing 8 projectiles in a radial burst and creating a puddle of harmful Brown Creep where she lands.
 * Only 2 puddles of Brown Creep can persist at once.
 * Spits two Bombs at Isaac. The range of these bombs is dependent on how close Isaac is to her.
 * Farts, creating a ring of explosive gas around her location.

Trivia

 * Colostomia is based on a Colostomy bag, a removable, disposable bag that attaches to the exterior opening of a colostomy to permit sanitary collection and disposal of bodily wastes.
 * Colostomia is confirmed female according to messages from Not Your Sagittarius in the official Binding of Isaac Discord.
 * Upon death Colostomia diffuses into the water of the arena, turning it from green to a murky brown.