Slowed Intestine Movement. Paralytic ileus is a type of ileus exactly where your intestines are struggling to move foods through them. Methadone might make this situation worse.​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​�