need help

what is the the matter with your digestive track when you burp and it smells like a fart?

[Kaneda2112]

You need to see a doctor to rule out intestinal obstruction.

Fecal breath odor typically accompanies fecal vomiting associated with a long-standing intestinal obstruction or gastrojejunocolic fistula. It represents an important late diagnostic clue to a potentially life-threatening GI disorder because complete obstruction of any part of the bowel, if untreated, can cause death within hours from vascular collapse and shock.

When the obstructed or adynamic intestine attempts self-decompression by regurgitating its contents, vigorous peristaltic waves propel bowel contents backward into the stomach. When the stomach fills with intestinal fluid, further reverse peristalsis results in vomiting. The odor of feculent vomitus lingers in the mouth.

Fecal breath odor may also occur in patients with a nasogastric (NG) or intestinal tube. The odor is detected only while the underlying disorder persists and abates soon after its resolution.

[Flycaster305]

I'm reinforcing Kaneda2112's post.  I experienced a bowel obstruction that resulted in emergency surgery to correct the problem, and it was indeed a life or death procedure.  However, in my experience, the backward expulsion of fecal matter is such a traumatic experience, the last thing you worry about is a foul breath order.  Usually, bowel obstructions are preceded by scar tissue from previous surgery(s) or tumors.   In my case, I was a boxer, and blows to the stomach created scar tissue.  

Just a thought, are you having your teeth cleaned regularly?  Poor dental hygiene can produce mouth odor like you are reporting.  Keep us informed.