It sounds like you described me. I had those exact problems with BC. When I got off BC the attacks continued to a much lesser degree and frequency. Now I take probiotics daily, I watch what I eat, I drink lots of tea, and I try walking at least a few times per week. That routine really has helped keep me regular and the number of attacks down. I do still get them, but probably only 1 every 6 weeks.
What Canyon suggests is great... A heating pad. I keep 1 at home and 1 at work. I use them for menstrual cramps AND "IBS cramps". If you know when you're going to get your period you could try taking a couple Advil (Midol, whatever) 2-3 days beforehand. My doc suggested it helps keep the aches, headache, and cramping to a minimal if you attack it a couple days ahead of time.
I also learned that if I can stay regular, I can prevent D attacks. I used to not go for days at a time, and then when I did finally go it would be an attack. I started eating yogurt (Activia) daily and taking probiotics. Those have now kept things moving which I suspect have helped keep the D at bay. My theory is that now when I get an attack there is less in there that has to come out. Instead of making 5-6 painful trips to the restroom, I will now only make 1-3 at most. When I get those attacks I try to relax with a heating pad and some type of calming tea. Like you mentioned, I think anxiety plays a lot into IBS. If you can relax, you can begin to feel better.
Again, like what Canyon mentioned, if your current antispasmodic isn't doing anything for you, ask for another.
I hope you feel better soon.
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