Period cramps and bowel cramps can feel very similar at this time. The cramping and diarrhoea you experience in your bowel at this time are brought on by the same chemical and can sometimes be mistaken for period cramps. The medical term for period cramps is dysmenorrhoea. Dysmenorrhoea is usually low-level pain in the lower abdomen, back and sometimes, thighs. The pain in your bowel that causes period diarrhoea is very similar due to the influence of prostaglandins. Sometimes the only way to distinguish between a period cramp and a bowel cramp is to sit on the toilet and let nature take its course!