Bloody Bowels of Hell

Jehan choo dantes inferno gluttony.jpg. Art by Jehan Choo

Hell can be depicted in many different ways. From the classic Fire and Brimstone Hell, where sinners burn for eternity, to a more organized structure with different sins punished in different ways, sometimes going all the way to torments personalized to the individual. Then there's this decidedly squicky version.

This kind of Hell is like being inside a living being, with walls of flesh and structures like organs. This is a fairly recent phenomenon which plays upon the Primal Fear of being eaten and the idea that Evil Is Visceral rather than ancient mythologies, but the idea of the entrance to Hell being an actual mouth that would swallow the damned is very much older than the use of the word "hellmouth" in Buffy the Vampire Slayer. (See this Hellmouth image from the Middle Ages.)

See also Womb Level, Evil Is Visceral.

Anime And Manga

 * The depiction of the Nexus from Berserk, where Guts and the Hawks wind up when Griffith calls the Godhand during the Eclipse, is very much one of these.
 * Inspired by the Divine Comedy, Saint Seiya's version of Hell is structured in several locations or "Prisons". The Sixth Prison is a lake of boiling blood, whereas those who sin of greed are devoured by Cerberus in the Third Prison.
 * Fullmetal Alchemist has the endless blood-filled Pocket Dimension inside Gluttony's stomach.

Card Games

 * While it does have a sky and thus isn't as claustrophobic as most of the examples here, the terrain in the hellish shard-plane of Grixis in Magic: The Gathering is said to made of bones and decaying flesh. Even its cities are referred to as "necropoli."
 * Phyrexia is a more straight example, complete with nine spheres.

Comic Books

 * In "Bio Apocalypse" the entire planet becomes this due to an experiment gone wrong.
 * In Aquaman, the purgatorial dimension of "The Others" resembles this in it's true form. Though they usually mask it with whatever time period or genre setting fits their momentary fancy.

Film

 * The Frighteners showed Hell to be the bowels of a gigantic eldritch worm filled with tentacles.

Literature

 * While Inferno in Dante's The Divine Comedy was mostly the more traditional Ironic Hell, murderers and tyrants are punished by immersion in Phlegethon, a river of boiling blood, and Judas, Brutus, and Cassius were given the special privilege of being Satan's personal chew toys. And we're not speaking figuratively. He has all three of them in his mouths and is chewing on them for eternity.
 * Said final section of hell is also frozen over. No sign of flying pigs, however.
 * In the third book of the Silverwing series, the bat version of the afterlife is relatively nice. However, those who especially displease the god of the underworld, Cama Zotz, spend the rest of eternity in his digestive system.
 * Played with slightly In Clive Barker's Imajica, as it's like being inside a *dead* being. The First Dominion (where the souls of the dead travel)

Live Action TV

 * The descriptions of Hell on Supernatural vary, depending upon who's describing it. However, in the second season, one demon  describes it as "a prison made of bone and flesh and blood and fear."

Tabletop Games
""This plane is sentient, and Prime-like, but with fleshy ground""
 * In the Dungeons and Dragons Planescape multiverse, some layers of the abyss are like this. Zegrentilandib


 * Layer six of the Nine Hells of Baator is Malbolge, formerly a boring place of boulders rolling down an eternal slope, ruled by the Hag Countess, who wasn't even a real devil. Then came the Fiendish Codex II, when the Countess was replaced by Glasya (daughter of Asmodeus himself), who did some remodeling. Now Malbolge is largely made up of its former ruler and sports distinctly fleshy terrain, with tall oily hairs instead of forests, lakes of bile and viscera, and ivory towers that used to be fingers or ribs. Special mention must also be made of a great mound at the layer's center called the Birthing Pit.
 * Then there's the realm of Torog, the King Who Crawls, god of imprisonment and torture. His capital city, as it were, is Gargash, the Living Torture Den. The reason it looks so horrible is that it's literally the not-quite-corpse of the ancient primordial that crippled and cursed Torog in the first place. It's "tended to" by an army of Wrackspawn, themselves the twisted not-angel-but-not-demon remnants of Torog's other victims, who are eternally hacking, destroying and reshaping the entire city-sized horror simply so that Gargash doesn't regenerate enough to let it wake back up.
 * Most parts of Malfeas, the Demon City, in Exalted don't look organic, but the place is nevertheless made of the of Malfeas', the fallen king of the Primordials, body turned inside out.

Video Games

 * Arc the Lad: Twilight of the Spirits has a handful of later battles in such a place.
 * The first Devil May Cry takes Dante to the Underworld near the end of the game, which is very much this. It's quite creepy, though the music that's playing more than makes up for it.
 * A lot of the levels set in Hell from Doom and Doom II are like this.
 * As well as parts of Doom 3.
 * There is a browser based MMORPG called Nexus War which has two "Evil" planes. The first is on the back of one of the pantheon of gods. From there you can descend into the second evil plane which is within said god.
 * The Hell level in God of War is distinctly covered in gore.
 * The computer game Ancient Evil has a variant—the walls of Hell are made of what seem to be human flesh and bone, with a pond forming from the blood.
 * The Secret of Monkey Island features such a setting in the caves beneath Monkey Island, referred to in a later game as "The Caverns of Meat."
 * While not strictly "Hell" in the traditional sense, the pain elemental Chzo (a.k.a. "the King") from the Chzo Mythos games is not so much an entity as an entire hellish dimension, a labyrinth of fleshy tunnels from which there is no escape. That, FYI, includes death: Chzo feeds off of suffering, and he not only tortures his prisoners into becoming mindless, mutilated slaves, but he keeps them alive for all eternity.
 * The "natural" dungeons inside the Oblivion Gates in The Elder Scrolls IV have a distinct organic drift, although not actually Hell, while the buildings are more similar to Alien Geometries.
 * While not the entire Hell, the ultimate punishment for gluttony in Afterlife is "The Bowels of Hell", where the damned are stitched to a demon's stomach and forced to eat the hideous food he consumes. The structure description is even interrupted by the narrator vomiting.
 * The Dark World in Silent Hill 3 and The Room. Naturally, it's very symbolic.
 * The Danger Zone in Legendary Wings.
 * Gluttony in Dantes Inferno.
 * The Claret Hollows in Etrian Odyssey.
 * The Domain of Pain in Guild Wars.
 * The Womb in The Binding of Isaac.
 * Hell in the first Diablo consisted of what seems to be bony walls filled with blood. The Nest in Hellfire was even more organic, but less infernal.
 * Averted Trope in Diablo II, where some parts of Hell look like islands floating in the void.
 * While not a straight example as he's not in an actual hell, the main protagonist of Saya no Uta sees everything and everyone in "gore-o-vision" after strong head trauma. Predictably, this starts to eat away at his sanity, until he meets a young girl who looks perfectly normal despite everybody else looking to him like horrible fleshy monsters...
 * Infinity from Breath of Fire II is the game's Hell analogue where Deathevans and his demon horde are Sealed Evil in a Can, and is completely made out of pulsating flesh.

Web Comics

 * Jack has all kinds of hell, but Drip's lair certainly fits this trope.
 * The Land of Pulse and Haze in Homestuck.
 * Vast swathes of the Black Bug Room that is Kano Jurgen's mind comprise cavernous rooms made of red, lumpy, veiny flesh. The doors to some of these are even labeled for your convenience.
 * Demon Eater might qualify, although it's ambiguous whether this actually Hell or merely another dimension with an utterly bizarre ecosystem. So far at least we've never seen any humans there, alive or dead.

Web Original

 * Orion's Arm: The Queen of Pain.