Does having MS affect any procedure?

Thanks for your inquiry,  honestly it depends on the control of your disease and your symptomology because each person's disease is unique. I have performed tummy tucks on numerous patients with multiple sclerosis without complication.  Please get medical clearance from your neurologist before proceeding, good luck.  

Thank you for the question.  
Based on your description of stable multiple sclerosis (and having obtained "medical clearance" from your neurologist), you should be able to proceed with elective surgery. I think you'll find that most well experienced board-certified plastic surgeons will have had significant experience  helping patients with multiple sclerosis achieve their desired outcome.
 Once you have choose your plastic surgeon carefully, everything else including good judgment/advice/planning, anesthesia provider and safe surgery facility will follow.  Concerns such as interaction of certain medications and avoidance of certain medications often used during surgery (anesthesia) should be carefully considered.
 Generally I suggest that patients start with the American Society of Plastic Surgery and/or the Aesthetic Society of Plastic Surgery to obtain a list of well experienced board-certified plastic surgeons.
Then, I would suggest you visit a few surgeons whose practices concentrate on aesthetic surgery. 
***Ask to see lots of examples of their work and preferably speak/see patients who have had similar procedures done.  Reading online reviews can be helpful in this regard also. Ultimately it will be important that you feel comfortable that your plastic surgeon have a significant/demonstrable experience consistently achieving the types of outcomes you will be pleased with.   
Besides appropriate training and experience (and certification by the American Board of plastic surgery), looking at before/after photographs (and preferably talking to previous patients) can be very helpful in this selection process. 
 Basically, patients should look at the overall "quality"  (as well as quantity) of the outcomes achieved;  in other words, it will be important that patients see lots of examples of outcomes that they would be pleased with.  In doing so patients will be able to get an idea of each  plastic surgeon's "aesthetic sensibilities".
 I hope this helps.