You may need to call your Dr, especially if you start having stomach pain or vomiting, or (sounds gross) breath with the odor of stool. Sometimes when you are constipated you can develop a bowel block (stool that has become so hard and large that it actually won't pass through your bowel) and liquid will pass around it and diarrhea can develop as your body tries to expel the waste. This may be true especially if you didn't have any solid stool at the beginning of your diarrhea. This can be a very serious condition if not treated and, in every patient I have dealt with, requires medical attention and hospitalization. Good luck and I hope this helps!