In the total picture the numbers are small. But there are some, for instance, in which the esophagus may end in a blind pouch and not reach the stomach. There may be a hiatus hernia, meaning there is a larger than normal hole in the large muscle sheet, the diaphragm, that separates the chest and abdominal cavities. Often this allows “reflux” or a regurgitation of acid contents from the stomach into the lower end of the esophagus, causing symptoms such as vomiting and failure to thrive
There are various other kinds yet like Meckel’s diverticulum, often talked about, but rarely seen. It’s like a huge appendix occurring along the bowel. Symptoms similar to appendicitis may arise if it becomes infected, but usually it silently stays there, causing no fuss or bother. Sometimes little growths called polyps grow on the lining of the large bowel.
A condition called megacolon, or Hirschprung’s disease, means that the last part of the large bowel is abnormally dilated. Fecal material simply collects here, increasing the mass until a huge amount has accumulated. Obstinate constipation occurs and finally surgical removal may be necessary. It is rare. I have encountered only one case in general practice in 35 years. This was in a male aged about 20 years, and it looked as though he were pregnant! He wasn’t of course. An operation cured his problem.
Some babies are born with no anus. The condition is called imperforate anus. This is usually picked up at birth when the baby is being examined by the obstetrician. It may be associated with other congenital abnormalities. Many of these conditions are rare indeed, and most mothers will never see them.