Oh... Oh damn... Gah...
You're so right. That was not, not pretty. And I don't just mean the images. The implications... Punishment (and a monstrously cunning one) for a long-forgotten crime, probably committed tens of thousands of years ago, calling you right back after all that time, literally sucking you in... Dear Eru... And did you notice? Some of the holes we see in the beginning of the manga are child-sized. Guess I just upped the nightmare fuel for you, huh? Hmm... Suddenly, some of those riffs in that Gorillaz MST you did with Laburnum make a lot more sense.
Here are two links for you. Keep in mind, however, that the fact that I post them does not mean that I'm forcing you to read them, or even take a look. There's some heavy material in there. Be warned.
First up, meet Tomie. This manga contains body horror to rival Uzumaki, plus lots and lots of gore, including multiple incidents of (live) dismemberment. There are also multiple instances of (female) nudity. I won't give away any spoilers, but I will say this about chapter seven, the first one in volume two. If I had to choose between carrying a chest-burster and carrying that... thing... I would definitely take the first option. Sure, I'd die, and messily at that, but at least it wouldn't cost me my soul.
Alternatively, you could just click this link: Scary Halloween Manga. It's the site where I found Tomie, and it houses a grand total of twenty-one different horror manga, some by Ito. Now, you must know that aside from Flesh-Colored Horror, these stories are unfamiliar to me, so you'll have to proceed on your own discretion. As for Flesh-Colored Horror, it's a collection of six unrelated stories, called Long Hair in the Attic, Approval, Beehive, Dying Young, Headless Sculptures, and Flesh-Colored Horror itself. Scared me something fierce. Blood and body horror aplenty, yet again. Tread with caution.