It was most likely a disease of the uterine lining (endometrium).
An infection of the endometrium is calledendometritis.
Postpartum people can develop several different infections of the reproductive organs, including some related to surgery.

Illustration by Danie Drankwalter for Verywell Health
However, the most common is still endometritis.
People will often have vaginal bleeding and a foul odor coming from the vagina.
Sometimes there is white or yellow discharge from the incision.
A severe infection can spread deeper into the abdominal cavity.
Or, the skin may turn black and blue and peel away.
Urinary Tract Infection
People often complain of pain and burning with urination when they develop a UTI.
Other symptoms can include lower abdominal pain and fever.
What Causes Puerperal Fever?
There are several risks to developing an infection after delivering a baby.
Other risk factors include:
Endometritis is an infection of the uterine lining.
The uterine lining, along with thefallopian tubesandovaries, is part of the upper genital tract.
People who have a cesarean delivery are 5 to 10 times more likely to develop endometritis.
Postoperative wound and episiotomy site infections are often brought on by skin bacteria such asStaphylococcusorStreptococcus.
Catheterization is a procedure in which a tube is inserted into the urethra to collect urine from the bladder.
The most common organism that leads to a bladder infection isEscherichia coli, or E. coli.
Antibiotics treat all of the various conditions.
The choice of antibiotic depends on the infection location and the bacteria most likely causing the infection.
Healthcare providers also treat fevers with pain relievers like acetaminophen and ibuprofen.
In the hospital, they will often give people intravenous fluids.
The postpartum person also needs to rest.
Wound infections are also treated with antibiotics.
This is especially true in patients who underwent bladder catheterization during their C-section.
Future Infertility
People who develop endometritis are at risk for future infertility.
The most common of these infections is endometritis.
Other types of infections include wound infections and urinary tract infections.
If the conditions are not recognized and treated appropriately, they can be life-threatening.
Antibiotics treat them all, and generally these postpartum infections resolve.
Postpartum infections are much more easily treated when antibiotics are started early.
2014;7(3):98-102. doi:10.1177/1753495X14522784
MedlinePlus.Endometritis.
2018;8(3):e018479.
2015;2:CD001067.