First off, don't think that you're powerless. Regardless of what the school may tell you, if your son or daughter has an IEP and has been suspended or is facing expulsion, you have a great deal of control over what happens next.
Under th Individuals with Disabilities Education Act, students on an IEP must continue to receive education services when they are removed from their regulation education setting. Normally the removal is through suspension or expulsion. While the student is in removal, he or she may be placed into an interim alternative education setting (IAES). But wherever that student is, the IEP still must be followed. This means that, even during removal, a student must continue to receive services while they're out of school.
In special education law, there occasionally is some confusion among parents as to what it means to be a child with a disability. An important thing to understand is that the definiction is quite broad.
This article raises questions about 504 plans and/or IEPs: Parent Sues School District Over Service Dog For Son With Cerebral Palsy. In this case, a parent of a child with a disability is suing the school district because the district isn't allowing his child to bring in his service dog. I have yet to see anything like this in the Denver area, but it wouldn't necessarily surprise me. Many people may look at a story like this and think it's ridiculous, but it actually raises some important questions.