Page 136 - Primary Five Science

Although the large intestine does not have villi, it absorbs

mainly water from the undigested food and forms stool to be

eliminated

The rectum collects the stool and signals the brain when it’s

full so that defecation can take place

The anus is the muscle that releases the contents of the rectum

when you go to the toilet.

Digestive System Diseases and Disorders

Diarrhoea

This is a condition of frequent water stools.

Diarrhoea is caused by;

 Underlying diseases such as cholera, typhoid, etc.

 Eating certain foods or food combinations that irritate the

digestive system.

 Some medications and drugs especially antibiotics, alcohol,

etc.

 Low or absence of beneficial bacteria. As these bacteria feed

on our food, they break it down then it’s easily digested.

These good bacteria may be killed by our immune system,

drugs or other bad (disease causing) bacteria. When this

happens, you get diarrhoea.

Dysentery

This is an infection of the intestines by bacteria or protozoa re-

sulting to diarrhoea with blood and mucus in the stool. This

leads to dehydration and anaemia.