In a video posted on Instagram, the comedian, 40, could be seen lying on a hospital bed having undergone a hysterectomy this weekend.
Speaking to the camera, Schumer said that it was "the morning after my surgery for endometriosis and my uterus is out."
She added: "The doctor found 30 spots of endometriosis that he removed. He removed my appendix because the endometriosis had attacked it.
"There was... a lot of blood in my uterus and I'm, you know, sore and I have some, like, gas pains."
Schumer, who has a 2-year-old son, has spoken before about her battle with endometriosis.
The condition, which affects one in 10 women of reproductive age worldwide, sees tissue similar to the lining of the womb start to grow in other places, such as the ovaries and fallopian tubes.
The main symptom of the condition, for which there is no cure, is pain, which may be felt in the abdomen, during sex or when urinating.
While a hysterectomy — which another endometriosis sufferer, Lena Dunham, also chose to have — might help ease the pain, there is a chance it can return. The procedure also leaves women unable to get pregnant.
In addition to the clip, Schumer shared a picture of her posing with her hand on her hip in a hospital gown and blue latex gloves.
"If you have really painful periods you may have #endometriosis," she captioned the post.
It has received more than 260,000 likes with many social media users rushing to offer words of support.
Padma Lakshmi, who has spoken about her own struggle with the condition, wrote: "Thank you so much for sharing your endo story. Over 200 million women worldwide suffer with this. Hope you feel better soon!"
Schumer spoke previously about suffering from endometriosis, noting that it had caused complications while she gave birth to her son Gene in 2019.
Speaking to the Informed Pregnancy podcast, she said: "I was throwing up through the whole first hour of my C-section. It's supposed to take about an hour and a half or something but mine took over three hours because of my endometriosis."
Schumer underwent IVF to have a second child, but revealed in August 2020 that she and husband Chris Fischer had decided against continuing the process, which had been "tough" on her.
They married in February 2018 and announced later that year that they were expecting a child.
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Video courtesy of NBCUniversal/Access Hollywood.