guts, bowels, intestines, viscera
膓 centers on the internal digestive organs: guts, bowels, intestines, and viscera. It refers to the soft inner parts of the body collectively.
膓 is a variant form of 腸, combining the flesh radical ⺼ with 昜, which likely contributes the sound. The character is historically associated with intestines.
The flesh radical ⺼ on the left indicates a body part, and the right side 昜 looks like a tangled mass. Picture the tangled, fleshy tubes inside the belly: guts and intestines.
For チョウ, imagine a long intestine stretching out like a chou (a made-up word pronounced 'choh') noodle: chou -> チョウ, and the tangled flesh radical reminds you of the guts.