I woke up this morning feeling fine. I felt the urge for a BM and went to the bathroom and suddenly had really bad cramping in my abdomen; it became worse. Suddenly I found myself on the bathroom floor waking up. I must have passed out. I rested the remaining of the morning. Now this early evening, I'm a still bit weak and lightheaded, otherwise fine. I did go for a short walk--a little over a mile--this afternoon. I'm usually a very healthy, active 59-year-old. Should I visit my doctor?