The lungs and the small intestine both have large surface area. Why does each of these organs need a large surface area? What task does each perform?

There are so many detox cleansers that im not sure which one to choose. I dont want to spend money on something that doesnt work. so does anyone know which one is the best and where i can find, especially ones in local stores like walgreens or walmart.

Though I’ve never been uber-regular, my periods have been very reliable lately. The past two months, though, I have missed them. (There is NO possibility that I am pregnant, so don’t ask.)

I have gotten my usual cramps the past two months, though, plus the chest pains that tend to accompany them. No bleeding, though.

Today, I developed severe rectal pains that were exasperated by applying pressure to a number of spots on my lower abdomen, especially in the form of sitting/laying down.

Could this possibly be endometriosis, and, if so, could this explain my missed periods?

Thanks.