For Your Information:
Kidney: As you're probably aware, humans have two kidneys, but need only one to survive. People may be born with just one kidney, or have one removed after injury or for a donation. In general, people with one kidney have few or no health problems, and have a normal life expectancy, according to the National Kidney Foundation. Technically, people can live with no kidneys, but require dialysis.
Spleen: The spleen filters blood and helps the body fight infections, but it's not essential for survival. The spleen can be removed if, for instance, it's damaged. However, people without a spleen are more prone to infections.
Reproductive organs: Women can have their uterus removed in a hysterectomy as a treatment for cancer, uterine fibroids, chronic pelvic pain, or other reasons. About 1 in 3 women in the United States had had the procedure by age 60, according to the National Institutes of Health. Men may have their testicles removed as a treatment for testicular cancer.
Stomach: The whole stomach is sometimes removed as a treatment for stomach cancer, a procedure called a total gastrectomy. In this procedure, the small intestine is connected to the esophagus. People who've had a total gastrectomy receive nutrition through a vein for a few weeks while they recover. After that, they are able to eat most foods, but may need to eat smaller meals, and take dietary supplements if they have problems absorbing vitamins, according to the National Health Service of England.
Colon: People may have their colon removed as a way to treat colon cancer or Crohn's disease, or in some cases, to prevent colon cancer. People can live without a colon, but may need to wear a bag outside their body to collect stool. However, a surgical procedure can be performed to create a pouch in the small intestine that takes the place of the colon, and in this case, wearing a bag is not necessary, according to the Mayo Clinic.
Appendix: The appendix is a small, tube-shaped organ that juts out from the first part of the large intestine. It's unclear what its function is, but it can be removed if it becomes inflamed or ruptures.
