Hello and welcome to eHealth Forum!

Understandably having unintentional bowel movement during sex can be embarrassing. This can happen without any cause or can be due to emotional trauma. If you are having heavy bleeding, then the cause could be fibroids of uterus. These can press on pelvic floor and cause both urinary and fecal incontinence.

If you have constipation or other bowel issues then these must be treated by a gastroenterologist. It helps some to go for a bowel movement before sex. Others are helped by tightly holding on to the anal sphincter-like you would do if you need to hold a bowel movement in a public place.

Talk to your husband and with mutual cooperation this can be overcome. Consult your gynecologist too. It is difficult to comment beyond this on net. Hope this helps. Take care!