I was on Effexor XL for almost 2 years at a really low dose for my IBS/anxiety - 75mg daily. I liked it a lot while I was on it. It helped curb a lot of my anxiety and I think that helped control my IBS somewhat. I eventually went off of it because I (1) felt better (2) was still having a lot of diarrhea and figured the meds weren't helping as much as I would have liked and (3) I was gaining weight from it- 10 lbs. Another thing that bothered me, at the time I was not good about
taking my meds at the same time every day. If I missed a dose of Effexor and took it a few hours later or missed one entirely, I got the brain shivers and a horrid headache. That was rough for me.
However, it never made me feel tired or listless. I had lots of energy. It barely affected my sex drive. The first few weeks were rough adjusting to the meds. I definitely had side effects, namely insomnia, diarrhea and headache. And I am not going to lie, the withdrawal for me was awful!! But, everyone is different of course. Plus, with your doc's help, you may be able to wean with very little problems if you ever have to.
If I were in your shoes and was needing/wanting meds, I would try it. You don't know unless you try, right? I have a friend that switched from something else..might have been paxil in fact...to effexor and she said she didn't have adjustment side effects. So, perhaps you may not even feel a change.
Good luck to you no matter what you choose to do!