Question

What is the hole in the stomach called? What is the cotton-like substance I find in there every 6-8 hours even if I take a bath?

Answer 1

When we are developing in the uterus as a fetus, we receive nutrients from our mother with the help of an organ known as the placenta. This placenta is attached to us by a tube known as the umbilical cord.

Complete answer:
The navel, also known as the belly button, is present in the abdominal region of the body. This navel is the portion where the umbilical cord is attached to. When a baby is born, the umbilical cord is cut off as the baby does not need nutrients from the placenta. Thus the portion of the abdomen to which the cord is attached will heal and form the navel.
The cotton-like substance that is found there is simply made up of lint or cotton fibers. Over time, the hair on our body rubs off a bit of cotton fiber from our clothes. This happens due to the friction of the hair and the clothes. This cotton fiber eventually goes and settles in the region of the belly button. There are also dead skin cells here.

Note:
The ‘hole’ that is present in the abdominal region of the torso is known as the navel or the belly button. It is the place where the umbilical cord is attached to. The cotton substance that collects there is cotton fiber.