Hi, Though it is common for some variation to be seen in the bowel habit during pregnancy, it is unusual to have diarrhea as such unless there is some infection or high fiber in the diet. Pressure of the growing uterus is felt on the pelvic organs like the bladder and rectum until the uterus remains within the pelvis, i.e., up to 12 weeks. Once it becomes an abdominal organ, such effects are rare. Please consult your specialist to see if there is any modification needed in your diet and medication as iron supplements can sometimes create such a state. Any infection also should be attended to. Hope this helps.