"underwent changes" is a correct and usable phrase in written English.
You can use it to describe a situation in which something has been altered or transformed in some way; for example, "The development of the city underwent dramatic changes over the past decade."
After the middle of the Kamakura period, the farming villages in which the warriors resided underwent changes as agricultural practices advanced; other aspects of society were changing as well.
Ownership of the means of production also underwent changes.
Sculpture underwent changes very similar to those in architecture.
Another theory is that plankton that initially could not digest the algae underwent changes that enabled them to.
In the 19th century the guitar's body also underwent changes that resulted in increased sonority.
The state's cultural landscape underwent changes as well, signifying a greater consideration for minority populations.
The populace, most of whom were farmers, also underwent changes in status.
The original text, written prior to 1536, underwent changes in 1612, ordered by Sultan Abdullah Maayah Shah.
Soviet Turkic languages also underwent changes, adopting Russian elements, but mostly maintaining the established Arabic-Persian vocabulary.
As the training of the physician underwent changes from the apprenticeship system to formal educational courses, so did the training of the pharmacist.
Notre Dame held the No. 1 spot in the Associated Press poll yesterday for the third straight week, and surging Tennessee replaced Connecticut at No. 2. The poll underwent changes throughout, with Arizona State earning its first national ranking in nine years and Arizona and North Carolina State returning after one-week absences.
