Amytriptiline is one of the "older" types of antidepressants, but does have pain relieving properties and is often prescribed for chronic pain patients, so it may be of benefit to you. One thing, however: it's a sedative so you'd best take it at bedtime. Beyond that, I'm not sure how long it takes to work or how long you'd have to stay on it. But if spasms are causing you pain and interferring with your sleep, it might be worth a shot.

That being said, there are other types of antispasmodic drugs such as bentyl, which are not antidepressants. That could be something to try first if you haven't already.