The Innards of Buu (魔の迷宮!!ブウの腹に何がある!? Ma no Meikyu!! Bū no Onaka ni Nani ga Aru!?) is the twentieth episode of the Fusion Saga and the two hundred seventy-third overall episode in the original dubbed and the uncut Dragon Ball Z series. The episode first aired on August 2, 1995. Its original American air date was November 14, 2002.
The episode begins with Vegito absorbed by Super Buu and falling down inside him. On the Sacred World of the Kais, Kibito Kai is disappointed that Vegito "failed", as he believes that his failure will result in the universe's destruction. But then Old Kai points out that when other people were absorbed, Buu took on those people's traits. Vegito, while seemingly absorbed, was not showing traits through Buu, meaning that he was in fact not absorbed.
Meanwhile, Super Buu is busy having a blast and causing mass destruction, while Dende, Mr. Satan and Bee are all frustrated that Vegito had been defeated, and Dende seemed to be very desperate for another chance. Mr. Satan is getting frustrated at Dende for not protecting the Earth, as he is its guardian. Super Buu then notices that he did not change after absorbing Vegito. Buu then admits that Vegito was pretty tough to eat, and that he might take a while to digest. He also exclaims that he will be given great power upon fully digesting him. The inside of Super Buu's body is then shown, all the way down to where Vegito is, with a Saiyan Shield around him to protect himself. Old Kai then realizes that Vegito deliberately got himself absorbed so he could find and rescue Gohan, Gotenks, and Piccolo.
In Super Buu's body, Vegito lets down the barrier, and suddenly, there is a huge blast, which makes Goku and Vegeta separate and fly apart in opposite directions. "Why'd we separate once we let the barrier down?" asks Goku. Vegeta has no idea and Goku states that it is strange because once they had the earrings on, they should not have separated. Vegeta, relieved that they are separated, crushes his earring in his fist, which angered Goku. Vegeta replies that there's no use arguing over it, reminding Goku that Buu could destroy the universe any minute. Goku agrees to follow him, and crushes his own earring in his hand.
Vegeta comes to be very agitated at Goku's observant behavior. Then Vegeta steps in a moist substance, sinking through it. Goku tries to help him out, but gets stuck himself. After falling through, they find that they are in Buu's stomach, along with all the candy and sweets Buu has eaten. Vegeta manages to climb out, but Goku stays behind for a moment. Unbeknownst to Goku, his lower body is currently burning. Upon smelling the scent, he asks "What's cooking?". Vegeta yells at him, claiming that he is being digested, and Goku jumps out. Then, they see a whirlpool up ahead, and they are tossed into the stomach acid, but Vegeta uses an energy ball to blow a hole.
After they escape, Goku tells Vegeta that they should be more quiet down there so that Super Buu does not notice them, and then Vegeta says that they should not have just crawled down that hole like mice and then tells Goku to hurry up and move it, and Goku makes a sarcastic remark ("I dunno how I ever get along without you, Vegeta") and follows. They are still walking through the stomach area and Goku says "How does he do it? I don't understand why he doesn't just keel over from eating so many sweets." Vegeta responds "You have no room to talk, Kakarot, oh, I've seen you eat dessert. And as bad as it seems, I'd much rather be down here than in your stomach after one of your pig-out sessions." Goku scratches his head and starts laughing and says "You're kidding!" and Vegeta responds "No, I'm not," in a serious tone.
They hear a strange noise and enzymes that have the appearance of green globs start closing in on them. Vegeta says "It's possible that these things break up all the food and what not that doesn't make it into the digestive system". Goku crouches to talk to them, but he does not have much luck because they are "objects" and cannot speak. One glob jumps on Goku's arm and starts burning it, Goku pulls it off and throws it to the side. Vegeta cracks up and says "Oh, he almost defeated the mighty Kakarot!" and then Goku laughs and says "Get out."
The globs start coming by the millions and Vegeta says "You obviously have a sweeter scent than mine, Kakarot, they seem to be attracted to you." Goku says "Aren't I lucky?" sarcastically, and then after a few seconds he says "Uhhh, Vegeta? Since there are about a million of them, you wouldn't mind helping me out, would you?" "Who, me? Of course not," says Vegeta "I'm a team player" and he grins. Goku gets sort of offended and says "Hey seriously! This could get ugly." Then, the green globs attack them, and they push at them. There are too many enzymes to count and they all cover Goku until he is totally covered in green globs. Goku is yelling in pain, and Vegeta is getting frantic. There is an earthquake, and a roundworm soon comes up. The giant worm is communicating with the slime covering Goku, and opens its mouth to eat Goku.
- This episode had the lowest rating for the Dragon Ball Z series on Fuji TV, with 12.1% rating share.
- Near the beginning of the episode, Super Buu destroys the TV that people are shown watching the Cell Games on.
- In the Ocean dub, while surveying the food eaten by Super Buu, Vegeta says "This is revolting. Not a vegetable in sight." This may be a play on names, with Vegeta's name being derived from the word "Vegetable".
- When Super Buu goes on a rampage destroying cars, it appears that the cars are all in perfect shape, even on the road. The cars should have been blasted through when Super Buu used his Human Extinction Attack to kill the drivers.
- The area where Master Roshi died during the battle against King Piccolo is seen being destroyed by Super Buu's destruction spree.
- An egg is seen stuck between two branches when Vegeta says "As bad as it seems, I'd much rather be down here than in your stomach after one of your pig-out sessions." However, Super Buu is not seen to eat an egg. The only time that he turned someone into an egg was when Chi-Chi annoyed him on Kami's Lookout and crushed her. Although this egg-like object may have been another sweet eaten by Super Buu.
- This is the first episode to use music from Fusion Reborn.
- In one scene, when Super Buu's stomach is blown by Vegeta it is seen that Super Buu has no apparels(Gohan's) on his upper body.
- This episode picked up where "The Incredible Fighting Candy" had left off.
- The roundworms and slime are exclusive the anime and are entirely absent in the original manga.
- Goku and Vegeta are defused in this episode.