Suggest Remedy For Frequent Bowel Movements And Vomiting

I have episodes of feeling sick, going to the bathroom for a bowel movement. while on the toilet I break out in a cold sweat, feel like I am going to pass out. I have to lay down then get back on the toilet, I also have to vomit. After about an hour, on toilet and vomiting I feel back to normal. I get these episodes about 4 times a year. I was prescribed Zoloft. Doesn t seem to help. Any suggestions? I am a 65 yr old female.