1 lactase intolerance, and. 2  malabsorption of certain foods. 3  Much of the gas generated is due to microbial breakdown of foods so that gases, for example, hydrogen, carbon dioxide, and methane are generated; the odor is from other trace waste gases or compounds such as skatole and sulfur-containing substances.
Best Answer: Blood enters the heart through the right atrium, it then goes into the right ventricle to be pumped via the pulmonary artery to the lungs to be re-oxygenated. After that it heads, via the pulmonary vein, to the left atrium in the heart to be pumped around the rest of the body again via the aorta.
Left Side of the Heart. 1  The pulmonary vein empties oxygen-rich blood from the lungs into the left atrium of the heart. 2  As the atrium contracts, blood flows from your left atrium into your left ventricle through the open mitral valve.3  When the ventricle is full, the mitral valve shuts.he pattern described below is repeated over and over, causing blood to flow continuously to the heart, lungs, and body. Right Side of the Heart. 1  Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart.