diaoreaha why are the faeces very liquid?

Answer 1

Increased amounts of water in stool can occur if the stomach and/or small intestine secretes too much fluid, the distal small intestine and colon do not absorb enough water, or the undigested, liquid food passes too quickly through the small intestine and colon for them to remove enough water. Of course, more than one of these abnormal processes may occur at the same time.

For example, some viruses, bacteria and parasites cause increased secretion of fluid, either by invading and inflaming the lining of the small intestine (inflammation stimulates the lining to secrete fluid) or by producing toxins (chemicals) that also stimulate the lining to secrete fluid but without causing inflammation. Inflammation of the small intestine and/or colon from bacteria or from ileitis/colitis can increase the rapidity with which food passes through the intestines, reducing the time that is available for absorbing water. Conditions of the colon such as collagenous colitis can block the ability of the colon to absorb water.