Bowel motions

The small intestine absorbs food nutrients. The waste is pushed into the large bowel where water is removed. The resulting faeces (poo) are temporarily stored in the rectum before being expelled from the body via the anus. The medical names for the expulsion of faeces include defecation and egestion. Water makes up about three quarters of faecal content, while the rest is composed of solids including undigested fibre, intestinal bacteria and dietary fats. Many illnesses and events can affect the colour and texture of faeces. Always see your doctor if you experience changes in bowel motions that don’t resolve within a day or two. Seek urgent medical attention if your stools are bloody.

Normal adult bowel motions described
Characteristics of the normal, healthy bowel motion include:

• Bowel motions should be firm, moist and easy to pass.
• Regularity differs from one person to the next - the range of ‘normal’ includes once per week to several times every day, depending on the individual.
• The average adult produces between 100g and 180g of faeces every day.
• Bowel motions are brown because they contain bile pigments (stercobilin).
• Bacteria use chemical reactions to break down the faeces. These chemical reactions produce smelly compounds like hydrogen sulphide, which account for the characteristic odour.

• Red - blood smears on the toilet paper are usually caused by haemorrhoids or anal fissures. Bright red blood in the faeces (haemotochezia) usually means internal bleeding, and the causes could include bowel cancer or a bleeding stomach ulcer.
• Black - one of the most common causes of black faeces is taking iron supplements. However, bleeding higher up in the digestive tract, such as from the oesophagus or stomach, can cause the faeces to appear black (melena). The cause could include bleeding from an ulcer.
• Maroon - blood is the usual cause of maroon-coloured faeces. Some of the causes can include bleeding from the bowel - often from diverticulosis, angiodysplasia (abnormal and leaky blood vessels in the intestinal lining) or bowel cancer.
• Cream or light coloured - light-coloured faeces usually means that bile salts are absent. This could be caused by a range of digestive diseases affecting the pancreas, gall bladder or liver. Hepatitis, for example, can make the faeces appear silver, white, grey or yellow.

• Watery - short bouts of diarrhoea can be caused by a range of factors, including food poisoning, gastroenteritis and anxiety. Chronic diarrhoea can be a symptom of more serious illnesses such as coeliac disease, inflammatory bowel disease, diverticulosis or bowel cancer. It can also be caused by medication, diet (high fibre diets, coffee and diet soft drinks can cause diarrhoea) and, frequently, from irritable bowel syndrome. Lactose intolerance can also cause diarrhoea, often with cramping and wind.
• Hard and dry - when you are constipated, bowel motions tend to be hard, dry and uncomfortable to pass. Common causes of constipation include a low fibre diet, and some medications. Constipation can cause haemorrhoids to produce symptoms because of the straining involved to pass a hard, dry motion.
• Stringy - parasitic infections of the gut can cause bowel motions to become thin and stringy. For example, worms can affect the faeces in this way.
• Greasy - a high fat meal can result in fatty, smelly faeces that tend to float in the toilet bowl. However, the constant passage of greasy stools could indicate a problem with fat digestion.

• The first bowel motion passed by a newborn is a greenish-black, sticky and tar-like substance called meconium. The faeces lighten in colour when feeding starts.
• The breastfed baby’s bowel motions can range in colour from yellow to light green.
• The formula-fed baby’s bowel motions can range in colour from creamy-yellow to dark green.
• Regularity can range from several times per day to once weekly, depending on the individual.

• Red - tomato soup, beetroot, red drinks such as cranberry juice.
• Black - liquorice, grape juice.
• Green - spinach, breast milk, formula milk.

• Medical history
• Physical examination
• Stool culture
• Small bowel biopsy for coeliac disease and lactose intolerance
• Colonoscopy or sigmoidoscopy
• Blood tests.

• Your doctor
• Gastroenterologist

• Water makes up about three quarters of faecal content, while the rest is composed of solids such as undigested fibre.
• Bowel motions should be firm, moist, easy to pass and coloured brown.
• Red, maroon or black faeces could indicate internal bleeding, so visit your doctor immediately.

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