Double stomach

A double stomach (ventriculus duplex) is an anatomical anomaly in which a person or animal has two stomachs instead of one.

The cause of a double stomach is a disruption in the process of fusion of two stomach primordia in the early stages of embryonic development. Normally, a single stomach is formed from two rudiments, but if there is an anomaly, they remain separated.

With a double stomach, both stomachs are connected to each other and have a common opening into the duodenum. However, the muscular layer and mucosa at the junction of the two stomachs are separated by a septum.

Typically, one stomach is larger than the other. The small stomach is located cardially, and the large stomach is located caudally. Sometimes there is a uniform distribution of volume between the stomachs.

Double stomachs are more common in pets, especially dogs. In humans, this is a rare congenital anomaly that can be combined with other developmental defects. As a rule, double stomach is asymptomatic and is detected incidentally during examination for other reasons.