Your symptoms sound like you have fecal incontinence. This condition is surprisingly common, affecting people of all ages but with higher prevalence in the extremes of age (infancy and the elderly). There are a number of possible causes for this so you should first seek out a good primary care doctor
, or gastroenterologist
. Your doctor will go through your medical history and perform a good physical exam. Of particular importance in your history includes the onset and precipitating factors. In your case, it appears to be overeating, but does this occur with certain type of foods (dairy, spices, caffeine, acidic etc...), type of day, or emotional stressors? Your doctor will also want to know how severe it is, such as the stool consistency (loose/constipation). Do you only have problems with stool or gas incontinence? Do you have any history of irritable bowel syndrome, inflammatory bowel disease (i.e. Crohn's, ulcerative colitis)? Is there a family history of similar problems? Have you had any procedures such as colonoscopy, or sigmoidoscopy, history of childbirth, or back surgeries? Any history of injuries to your back or neurological disorders like multiple sclerosis, diabetes mellitus, obesity, or urinary incontinence? Have you ever been checked out to see if you have rectal prolapse? Is there blood or mucous in the stool? After the initial history and physical examination your doctor may proceed with a colonoscopy. He or she may start with a trial of antidiarrheal agents, bio-feedback (neuromuscular training), or possibly surgery (sphincteroplasty if your anal sphincter is damaged). Please see a doctor soon.