What has happened to you is very complex.

A long history of medical interventions, along with drugs.
For example, Cipro causes neuropathy in some people.
The Merrem has listed hepatic side effects.

I have this post on our PN board here with ways to deal with the toxic side effects of Cipro and its related drugs:
http://neurotalk.psychcentral.com/thread54985.html

Do you have vomiting? other GI symptoms? diarrhea?
I am having a problem understanding the GI problem.
Can you list what you would eat now in a day?
Did you lose weight because you stopped eating?

Are your liver functions normal now?

In general doctors ignore the potential for drugs to cause problems in patients. Some people believe they do this because they don't want to admit to culpability.
Merrem can cause paresthesias, as well as Cipro.
I am thinking so far that you have a neuropathy. But you need to please answer more specifically what is the problem.

After surgery, patients need more protein to heal. You can get this easily with whey protein shakes. Also another element needed for healing is zinc.
I don't understand in what way you feel worse on a vitamin supplement. If you could be more specific with that --it would help clarify. Multivits typically have very little in them. So I don't understand what is making you feel worse.