GBS v. CIDP
I am no expert, nor am I a physician, but I have CIDP, and I have acquaintances who have GBS. I’ve learned a bit about both diseases. CIDP used to be characterized as the chronic form of GBS, but many neurologists no longer consider that to be the case.
GBS is usually more acute in its presentation. In general, it can be more serious, even life-threatening. Mechanical ventilation is sometimes necessary, and autonomic nerve involvement much more common. A full recovery is sometimes possible with GBS, but not as common with CIDP.
IVIG is a first-line treatment for both GBS and CIDP, but a friend of mine with GBS told me just today that IVIG is a very short-term treatment for GBS. Long-term treatment with IVIG is common in CIDP.
CIDP is most commonly relapsing/remitting or progressive; GBS is not. Others may be able to draw more distinctions for you between the two.