What is a stoma?

A stoma is an opening from either the digestive system digestive system or urinary system . This opening is the exit point for faeces or urine and is formed, surgically, to treat serious, often life threatening, diseases and medical conditions such as bowel or bladder cancer, inflammatory bowel disease (ulcerative colitis or Crohn’s Disease), diverticulitis, congenital abnormalities or injury.

There are 3 types of stoma – colostomy, ileostomy and urostomy.

• Colostomy
A colostomy is the result of an operation where part of the colon (large intestine) is brought out onto the surface on the abdomen. 
Food waste exits the body via the colostomy rather than from the anus. This waste is collected in an appliance that is worn on the abdomen, over the colostomy. These appliances are usually referred to as stoma bags.
A colostomy operation might be done because a section of bowel has had to be removed due to bowel cancer, inflammatory bowel disease, or injury.

• Ileostomy
An ileostomy is the result of an operation where part of the ileum (the last section of the small intestine) is brought out onto the surface on the abdomen.
Food waste exits the body via the ileostomy rather than from the anus. This waste is collected in an appliance that is worn on the abdomen, over the ileostomy. These appliances are usually referred to as stoma bags.
An ileostomy operation is done to treat medical conditions such as bowel cancer, ulcerative colitis, Crohn’s disease, Familial Adenomatous Polyposis (FAP) or injury.

• Urostomy
A urostomy is the result of an operation to divert the flow of urine from the usual route. In most cases a urostomy is formed by a section of small bowel being removed from the digestive system, and then attached to the ureters (which are the tubes leading away from the kidneys).  This section of bowel is then brought out onto the surface on the abdomen to form a urostomy.
The urine will then flow from the kidneys, along the ureters, through the section of bowel and out of the urostomy.  As it is passed from the urostomy the urine is collected in an appliance that is worn on the abdomen, over the urostomy. These appliances are usually referred to as stoma bags.
A urostomy operation is done when the bladder has to be removed, or bypassed, due to cancer, congenital or neurological disorders or injury.

Digestive system

The digestive system is a continuous tract that starts at the mouth and finishes at the anus. Its role in the body is to take in food, extract and absorb energy and nutrients and then expel the remaining waste.

This process starts with the mouth where food is chewed (mechanical digestion) and mixed with saliva which starts the chemical digestion process. Once the food has been swallowed it passes down the oesophagus (also known as the gullet, approx 25cm in length) which uses mucus and peristalsis to move the food towards the stomach. Peristalsis is the rhythmic contraction of muscles in the bowel which forces food along it. It is this action which causes stomas to move, and appear to shrink and grow. Once in the stomach the food is partly digested by gastric juices until it is a thin liquid (chyme). From the stomach food moves on to the small intestine.

The first part of the small intestine is the duodenum (approx. 25cm in length). From here, food passes on to the jejunum, (approx. 2.5m in length), and then the ileum, (approx. 3.5m in length). As food passes through the small intestine it is mixed with bile and enzymes which help to break food down further and then nutrients are absorbed for use by the body. This is the chief role of the small intestine. Once food has passed through the small intestine it moves into the large intestine.

The first part of the large intestine is the caecum. The appendix is attached to the caecum. After passing through the caecum, food then travels up the ascending colon, across the transverse colon, down the descending colon, and then into the sigmoid colon. As it makes its journey through the large bowel the water and salt content of the food is absorbed back into the body. The colon also secretes mucus to ease the passage of the food waste through the bowel. After leaving the sigmoid colon the food waste waits in the rectum until it is passed through the anus. Sphincter muscles around the anus control the passage of faeces and prevent leakage.

Urinary system

The urinary system removes waste from the bloodstream. Some of this waste comes in the form of urea. The urea and other waste are carried to the kidneys where they are separated from the blood. The waste products are then sent down the ureters in the form of urine. The ureters are between 20-25cm long and have strong muscle walls which pass urine along and release it into the bladder. The bladder is a hollow muscular organ which stores urine until ready to be passed through the urethra.