This was a problem that I first saw at the institution in Brooklyn. It happens too frequently in developmentally delayed children. Some of them find a way to regurgitate what they have eaten and then reconsume it. The behavior is disgusting and dangerous. People, you know, are not anatomically configured like cows. Bovines, it seems, functionally ruminate without harming themselves because of the structure of their digestive system. People do not have that structure. Vomiting brings up stomach acid. The stomach has a lining to protect against the acid which aids in digesting. The lining of the esophagus was never meant to be repeatedly in contact with stomach acid over a short period of time. The teeth are also harmed. There is danger of aspirating the vomit into the lungs causing other sorts of damage.
This is a long story, because it took me almost 15 years to come up with a solution. First, I went along with the most current treatment methods. These included paced feeding, which was continuous feeding of very small amounts of food that would be difficult to regurgitate. This sometimes worked, but required huge amounts of staff time and work. Another method involved using physical food characteristics to make rumination difficult. These kids were fed loads of peanut butter, which was sticky, heavy, and difficult to regurgitate. Kids can't live on peanut butter, not to mention the problems it would cause to someone with an allergy. That was in 1976.
In 1985, I found myself in the position of Director of Psychological Services at a small private institution in North Carolina. There was a 19 year old patient there who had Moebius Syndrome. This disorder involved the dysgenesis or agenesis of a portion of the 8th cranial nerve, and no innervation to the face. This guy could not cry, smile, or frown. His face looked like an unchanging mask. One thing that this guy could do was ruminate. He would eat, then sit in his rocking chair and ruminate. It was made even more disgusting by the fact that he would open his mouth so that the emesis was visible. The smell was awful, no one wanted to be near him to work with him, and he was really harming himself (his teeth were already severely damaged). I took a very brief baseline of his rumination, and then went to work. I had watched him a number of times, and noticed that his rocking had something to do with his ability to ruminate. I stopped his rocking in the chair, and his rates of rumination nearly disappeared. I thought that the rumination worked by making himself "sea sick."
Fast forward to 1991. I was working at a group home when I was asked to check on a six-year old girl who was ruminating. She would eat, and then engage in some very subtle movements that made me think back to 1985 and the young man with Moebius Syndrome. I did some research on motion sickness, and found something odd in an aerospace journal. The early space flights attempted by the Russians with dogs as passengers crashed because the animals got motion sickness, threw up, and damaged the wiring. The Russians solved the problem by removing the vestibular mechanism inside the dogs ears prior to flying into space. That worked. The dogs without vestibular mechanisms did not become sick during launch or in space. We could not do the same surgery on this little girl.
I thought, "What if we gave this kid some Dramamine (tm)?" I put in a request to accompany her to her next physical. I proposed the idea to her physician (a Medical Resident) who referred me to his supervisor. The supervisor and I had a brief discussion about space dogs, Moebius Syndrome and rumination. He decided to give it a try. Twenty minutes before eating breakfast, the girl took an appropriate dose of Dramamine (tm). She stopped ruminating for the whole day. The success lasted until I left and no longer had contact with the case. I don't think that this would work for every case. There are also more powerful anti-emetics to try (with more side effects).
This is an update. Recently saw a child between 1 and 2 years old (closer to 2) who was engaging in voluntary vomiting. I asked the mother to describe what he does before the vomit comes out. She described it: "First, he puts his hands down to grab the bottom of his seat. Then he shakes his head up and down (like indicating 'yes'). The vomit comes." Her instructions were to hold his head still (gently) from behind. This, by report of mother, paternal grandmother (reporting when her daughter in law was not home), resulted in a 100% cessation of voluntary vomiting. I recently came across a reference on line that might help to understand how the control of movement works: www.sciencedaily.com/videos/2007/0509-science_of_motion_sickness.htm