Quote Originally Posted by Kitty Cat View Post
Gp has suggested, switching AD to Venlafaxine, to help with anxiety, but I'm not sure of its effect on bowels.
I'm not a fan of venlafaxine. It has a number of potential issues including being to hardest AD to quit. Despite the SNRI claim it is really only a SSRI and any of those would be a better option, imho. Citalopram, or escitalopram would be the pick if you wanted to go down the SSRI path.

I'm on 40mg of Amytriptyline per day at the moment, which doesn't seem a lot, but I do suffer with some of the side effects of a TC, particularly weight gain, dry mouth, and palpitations.

Would going lower on the Amytriptyline and adding Venlafaxine help, or should I increase the amytriptyline a bit more and see if the side effects get any worse.
Increasing the amitriptyline dose would be the easiest option and likely to be the fastest to work on your anxiety. Another option would be to switch to imipramine which is also effective for IBS, but generally has less impact on weight and the muscarinic acetylcholine side-effects such as dry-mouth and constipation although, as with all things antidepressant, YMMV.