How common is it for somebody to get meckel's diverticulum?

Rare. The rule for meckel's is that 2% of the population is born with it. It occurs in the last 2 feet of small bowel. 50% of patients with symptoms will occur in the first two years of life. 50% of meckel's have gastric(stomach) tissue which makes acid and causes bleeding secondary to ulcers. This bleeding is painless.
2% of people. Meckel's diverticulum is a congenital anomaly of development of the intestine. It is present in 2% of the population. Symptoms from it are also rare, and also said to be about 2%.
2% Approximately 2% of the population are born with a meckel diverticulum.