MYO Fake Intestines
Find an old pair of natural color or sheer white/gray pantyhose and trim the "feet" off. Carefully fill the hose with cotton or cut up cloth (old bed sheets work well for this). If you want to give a really nasty view, add shells or other "sharp" looking objects. Using a hot glue gun seal the ends. Draw "Veins" with a red marker
Randomly twist your intestines and stitch them in various places to make them appear more realistic. Spray them thoroughly with clear varnish & let them dry. This will give them a nice glossy sheen.
Place some Fake Blood in a small spritz bottle, and spritz in several areas to give them that freshly gutted look. Hang them from a torn shirt, or let them hang out over the top of your pants as though you had surgery that the doctor didn't bother to complete!