A thin plastic tube like aquarium pump tubing. Could you do it if you could guide it properly?
Probably, for some kind of medical procedure... That's kinda disgusting though.
Not with something that size but yes, it can be done but rarely is. Even by medical professionals who carry out tests or examinations of the gastrointestinal tract. The chances of piercing the intestine are very real. To do so would likely result in Sepsis. The condition known as Septicemia can result in death within 24 - 48 hours if medical attention is not sought. Even then a cure of the blood poisoning that will occur may not be reversible. So in reality, it is a dangerous practice.
