Before I had my laparoscopy, I was told I might have endometriosis or a chronic case of pelvic inflammatory disease. How are these different?

Only 1 is infectious. Pelvic inflammatory disease is infection that can cause pain, scarring and "adhesions" from the pus which is collected bacteria and white blood cells. Treatment requires antibiotics to kill the bacteria. Even after the infection is gone however, scar tissue may remain. Endometriosis is misplaced tissue from the lining of the uterus, that settles elsewhere and bleeds at the time of the period.
Very different. If you had laparoscopy, you should now know what was causing your pain. Pid is infectious disease whereas endometriosis is not. Endometriosis and pid can easily be distinguished at laparoscopy. Chronic pid is actually not that common but the sequelae of acute pid is much more common which presents as adhesions.
PID vs Endo. Pid is a sexually transmitted disease that causes pain with menses and with intercourse, may block the tubes and cause infertility similar to what endometriosis(which is not infectious in origin)will do in the pelvis.

Related Questions

What are the symptoms of pelvic inflammatory disease? How are the symptoms of pelvic inflammatory disease different than sever symptoms of pms? .

PMS vs PID. Pid or pelvic inflammatory disease is an infection which starts in vagina or service and spreads to uterus, fallopian tubes and ovaries and to lower abdomen. It is usually due to untreated or neglected sexually transmitted disease. Pms is associated subjective feeling of fullness before or during periods and is associated with stomach cramps, pain, change in mood. No infection is involved periodic. Read more...

Can you tell if you had pelvic inflammatory disease? How do u kno you had it long enough to cause damage

No easy way. If you didn't have lower abdominal pain, you probably didn't have PID. This isn't certain; sometimes silent infection can damage the fallopian tubes, i.e. asymptomatic PID. However, most women with chlamydia don't have serious tubal damage. Unfortunately, there's no easy way to know for sure. Often the problem comes to light only after failure to conceive after a year or more of trying. Read more...