GIT foreign bodies are common in veterinary practice, and most patients suffering from these are dogs thanks to their greater propensity for dietary indiscretion (that phrase is so proper). Obstructive intestinal foreign bodies normally cause vomiting, but if they remain in the gut for too lung they cause pressure necrosis and destruction of the gut, gut perforation and peritonitis, and all kinds of systemic effects including sepsis. I had a lovely dog present to me a few weeks ago for vomiting. She didn't have a painful abdomen and was very bright but she was dehydrated so I admitted her to hospital and gave her IV fluids. The owner suspected the dog might have eaten pantyhose, as this dog was a serial pantyhose-eater (more on serial underwear eaters later - although there is one schnauzer I know who has had THREE separate surgeries to remove THREE separate pairs of underpants). This patient, we'll call her S, didn't vomit in hospital and seemed to improve once we hydrated her. So before removing the drip I test fed her with some bland food - and she pushed out the longest poo I've ever seen. It looked like a chocolate-coated licorice stick (see above), but on closer inspection I was able to confirm the presence of pantyhose. I think rehydrating the gut lubricated the passage of the offending pantyhose - which was fortunate. Many dog's aren't so lucky.
I thought this was an amazing poo story until I spoke to a client whose labrador (its no coincidence that labs are so often implicated - they eat anything) had eaten a doll. During a walk, the dog passed a stool and when the responsible owner went to pick it up off the footpath she observed - much to her horror - a single doll's eye, positioned in the centre of the stool, looking back up at her. At the time she wasn't aware of the fate of the doll so it wasn't something she had expected. Fortunately the remainder of the dog was not inside the dog so there were no complications. Just a very scary poo!