Poo is made of water, bits of food that could not be digested, dead cells from the lining of the intestines and dead bacteria – all the solids that the body doesn’t need or want any more. It is brown in colour because of bile from the liver but is darkened by iron and pigments in foods and red wine.

Green Poo in Babies

Some parents are alarmed when their newborn baby passes sticky, dark green poo in the first few dirty nappies. This is completely normal and is called meconium. Meconium is made in babies’ bowels before birth when they swallow and digest the proteins in the fluid that surrounds them in the womb (amniotic fluid). Although unborn babies pass urine into the amniotic fluid, they don’t usually open their bowels, so the meconium stays put until after birth. However, if a baby becomes distressed or short of oxygen during birth, their bowels will open. The amniotic fluid becomes green and is a signal to the midwives and doctors that they need to get the baby out quickly.
After these first few days, breast-fed babies produce runny, yellow-brown poo, and bottle-fed babies have more solid, darker brown poo.
‘Black worms’ in babies’ poo. Infants fed on banana mashed with a fork may appear to have black worms in their poo from the banana’s fibres.

Black Poo

If your bowel has a lot of iron-rich material in it, your poo will end to be dark brown or black. This can happen if you are taking iron tablets or have eaten a lot of red meat or black pudding. It can also happen if the upper part of your intestine is losing blood, in which case the blood is digested further down the intestines in the same way as food. Such bleeding can be due to an ulcer, irritation of the stomach from taking drugs like aspirin or ibuprofen, or tumours. If a lot of blood is being lost into the intestines, the poo becomes black and sticky, like tar. These symptoms should be reported to your doctor urgently so that you can be treated before the blood loss becomes too severe. The reason for the bleeding can also be investigated.

Red Blood on Poo

A common cause of seeing red blood streaked over the poo after opening your bowels is piles (haemorrhoids). These are swellings round the anus that contain blood and are common in women who have had a baby or in people who tend to be constipated. They can be painful or itchy. The skin over the surface of the piles is thin, so they bleed quite easily, although this is rarely more than a drop or two. In general, blood from piles is bright red. If you are unsure whether piles is the cause of red blood in your poo, then your doctor needs to make sure.
Piles can be treated. They can be injected with a chemical to make the blood inside them clot, or they can be removed surgically. However, they do tend to come back. The best way to combat this problem is to eat a high-fibre diet, ideally with five portions of fresh fruit and vegetables a day, to keep the poo soft.

Dark Blood in Poo

Occasionally, blood on or in poo can indicate bleeding in the bottom part of the bowel, which may be due to a more serious condition such as a tumour, colitis or diverticular disease. This blood is usually dark red, or in clots, or mixed with a lot of slime or mixed in with the poo. If you have this type of bleeding, it is wise to see your doctor, particularly if you are over 50. Other symptoms that might be serious are a decreased frequency and/or hardness of poo, or an increased frequency and/or looseness of poo.

Smelly Poo That Won’t Flush Away

Normally, when we eat, food is digested by enzymes in the intestines. There are different enzymes for different types of food, and those that digest fatty foods are helped by bile made by the liver. Sometimes the bile or enzymes are not made or can’t get into the intestines because of a blockage. This means fat in the intestine can’t be digested, and so it passes through the bowel where bacteria feed on it. The high levels of fat and the waste products from the bacteria will make the poo smelly, pale and frothy, and difficult to flush away easily.
Why does this happen? It can be due to a number of reasons. Coeliac disease, a condition in which you cannot tolerate protein found in wheat, can affect the intestines so they can’t absorb fat in the diet. In gall bladder disease, bile, which is normally stored in the gall bladder, can’t get into the intestine to help absorb fat. If your pancreas, which makes enzymes and insulin, isn’t working properly, fat won’t be digested. This can happen if you have chronic pancreatitis or a tumour in the pancreas. If you develop any of these symptoms, visit your doctor to see what is causing the problem. You may need to reduce the amount of fat in your diet or take tablets to replace the missing enzymes.

Pale Poo

Pale poo following an attack of diarrhoea soon returns to normal. They can also occur in jaundice – because bile can’t get into the intestines, the yellow colour builds up in the blood instead. Gall stones are often the culprit and are often associated with bad abdominal pains. However, the tube that feeds bile into the intestines may be blocked – this is not usually painful – or the liver may be inflamed (hepatitis). If your poo becomes pale and your skin or the whites of your eyes turn yellow, consult your doctor.
If in doubt, get checked out!


First published on: embarrassingproblems.com
Reviewed and edited by: Dr Kevin Barrett
Last updated: October 2020

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