May 20, 2012 · There are many causes of mucous in a baby's stool: -- an excess of swallowed mucous (from teething or a cold) --food allergies --malabsorption --viral or bacterial infections --intussusception (which is an intestinal obstruction generally accompan... Poor oral hygiene can cause your breath to smell like poop. Failing to brush and floss your teeth properly and regularly can make your breath smell because plaque and bacteria accumulate on and between your teeth. Gum disease can also contribute to foul-smelling breath. It's caused by neglecting oral hygiene. Blood can appear in stool in a fresh (hemactechial) or digested (mane) form.This aspect can helps us to locate its place of origin, which will help facilitate the reason why vomiting and diarrhea with blood is occurring. Baby diarrhea can be caused by a virus, infection, stress or a food intolerance. Green mucousy stool is a sign that baby's intestines are irritated. Teething can also be the culprit: When baby swallows a ton of drool, it can irritate the intestines and cause some mucus in the poop.