When is blood in the stools a cause for concern?

Doctor's Answers 3

Bleeding from the back passage is actually one of the most common complaints seen by doctors. The good news is that most of the time, the bleeding is caused by something non-worrying.

For example, most people who experience bleeding, as well as a bump around their butt crack may have a haemorrhoid (your doctor can easily confirm this during his examination).

The appearance, colour and smell of the blood can sometimes help doctors distinguish between causes. As a general rule:

1. Bleeding from the anus – the blood tends to be bright red and fresh. You may notice blood after passing faeces, or streaks of blood covering faeces.

2. Bleeding from the colon/stomach/intestines tends to be darker red and mixed in with your faeces, because the blood has to travel a longer way through the gut before it passes out. This is known as "melaena", and tends to be more smelly.

You can find out more about what to do if you notice bleeding from your back passage in this previously answered question.

Photo of Dr Wai Leong Quan
Dr Wai Leong Quan

Gastroenterologist

Whenever blood is found in our stools, it represents a breakage in the inner lining somewhere along our digestive tract. Blood can be present in our stools without being detected if it is in a small amount (occult blood). On the other hand, our stool colour may change to tarry black, maroon or even fresh red depending on the location and the rate of bleeding.

Common reasons for blood to appear in our stools include colon infection, haemorrhoids, small tears in the rectal mucosa otherwise known as anal fissure and ulcers along the digestive tract. The other more concerning cause is bleeding due to cancers.

Although fresh bleeding in large amount automatically calls for immediate attention, any amount of blood found in our stools requires proper assessment. This is especially so in anyone above the age of 50 or having a family history of digestive cancers. The mistake of delaying or deferring an early evaluation may result in detecting cancers at a later stage which carries a much poorer overall prognosis.

  • Dr Quan

Blood in the stools is always a cause of concern.

The most common cause of blood in stools is bleeding haemorrhoids. You can bleed from a variety of other causes as well.

Everyone is worried about the possibility of colorectal cancer.

While colorectal cancer tends to affect the older generation (above 50 years of age), up to 20% of colorectal cancer cases affect Singaporeans below the age of 50, some as young as 18.

If you notice bleeding in your stools more than once a week, you should speak to your doctor. If you have abdominal discomfort or altered bowel habit with the bleeding, you should consult your doctor soon.

Similar Questions

Where can I seek treatment for cystic acne in Singapore? What is the best cystic acne treatment?

Thanks for the very helpful picture. Your condition is typical of moderate to severe acne, due to the presence of active pimples, acne scars and comedones (or blackheads). The dark coloured, bigger lumps that you described is an infected cyst – the reason why it’s tender, swollen and dark coloured, is because your body mounts an inflammatory response to the clogged pores and trapped bacteria; similar to how your other pimples are formed.

Photo of Human

Answered By

Human

How can I prevent or minimise scarring after an insect bite?

In general, after an insect bite, it is important to minimize picking and scratching at the rash as this can aggravate the swelling and increase the risk of scarring. It is also important to prevent infection and keep the area clean. Topical antibiotics may be helpful especially of there is a wound and overlying redness. Some people may develop an exaggerated insect bite reaction and the area of the bite can become very inflamed. Topical steroids can help reduce the inflammation. For the current scar, this should usually get better with time. Silicone based scar gels may help in the healing.

Photo of Dr Colin Theng

Answered By

Dr Colin Theng

Dermatologist

Ask any health question for free

I’m not so sure about a procedure...

Ask Icon Ask a Question

Join Human

Sign up now for a free Human account to get answers from specialists in Singapore.

Sign Up

Get The Pill

Be healthier with our Bite-sized health news straight in your inbox