The ageing intestines

Malabsorption

• Many studies have demonstrated malabsorption of carbohydrates, lipids, amino acids, minerals and vitamins in the elderly. Intestinal absorption of (44)Ca and (67)Zn considerably decreases with age. 
• There is an age-associated increase in the prevalence of dyslipidaemia and diabetes. This could be related to a combination of declining dysfunction in digestion, absorption, and metabolism.

Herniation

• It is possible to develop weak points in the abdominal walls. Structures can escape from a high pressure cavity into a low pressure cavity through these weaknesses. This is known as herniation. A classic example would be a protrusion of intestines through the deep inguinal ring, into the inguinal canal and into the scrotum (indirect inguinal hernia). As a person gets older, the abdominal walls often become gradually weaker, and subsequently the rate of herniation increases with age.
• If the opening of a hernia becomes too narrow for the structure passing through it, the structure can lose its blood supply. This is called strangulation and it can lead to necrosis and perforation.

Diverticulosis

• The intestines are arranged as a circuit of pipes through which food moves. When there is a weakness in the wall of the intestine itself, the pressure of the intestinal contents causes the wall to bulge outwards. With time, this becomes a pocket of increasing size. This is known as a diverticulum, and the state of having many diverticula is diverticulosis. This is often asymptomatic.
• Diverticula can perforate, leading to peritonitis. 
• In some cases, a diverticulum becomes colonised by pathogens and inflamed. This inflammation of a diverticulum is known as diverticulitis. This increases the risk of perforation.