If you notice that your stool is black or gray in color, it could be as simple as a change in your diet or a sign of dangerous colon cancer. Even if you think you know why it’s happening, always call your doctor if you have black, tarry stools.

According to experts, melena—also known as black stool—comes from bleeding in your upper gastrointestinal tract and is a sign of old blood in your stool. Dr Mohit Saxena, consultant and head of the department of medical oncology, Manipal Hospital, told Times Now, “Black stools indicate bleeding from the upper gastrointestinal tract, such as the esophagus, stomach and small intestine or the first part of the duodenum.”

The blood becomes dark and cloudy as it travels up your GI tract from where it started – usually your stomach or upper small intestine. Digestive chemicals interact with the blood as it travels, changing its color and texture.

Black stool is an early sign of stomach cancerAccording to Dr. Saxena, you should not ignore it and immediately contact your doctor for further investigation. “Black stools may be a sign of an underlying malignant disease such as stomach cancer or esophageal cancer. “It should not be ignored, and the patient should consult a healthcare provider for prompt evaluation, including blood tests, imaging such as barium study or CT scan, upper gastrointestinal tract, and biopsy of a suspicious lesion,” he said.

Other possible causes of melena

According to Dr. Saxena, melena can also get into your lower esophagus if you swallow blood. Rarely, if your intestines move very slowly, this may be due to your lower small intestine or upper large intestine. Causes of upper GI bleeding and melena may include:

• peptic ulcer disease
• gastritis or esophagitis
• gastrointestinal perforation
• esophageal rupture
• Esophageal or gastric varices
• Esophageal, stomach, or periampullary cancer
• viral hemorrhagic fever
• iron supplement
• activated charcoal

Other symptoms of black stool that may indicate colon cancer

Some other signs and symptoms may indicate what is causing the bleeding or where it is coming from, such as:

stomach ache

This is an early warning sign of any condition like ulcer, gastritis, gastropathy or even stomach cancer.

vomiting or bleeding

Some people also vomit blood. According to experts, fresh, red blood in your vomit indicates active bleeding in your stomach or esophagus. Dark brown, textured blood that resembles coffee grounds is old and indicates that bleeding has stopped.

Other symptoms of stomach cancer

In stomach cancer, also known as gastric cancer, cancer cells in your stomach grow out of control. Doctors say most cases of stomach cancer are caused by abnormal cell growth at the spot where your stomach meets your esophagus. some common Symptoms and signs of stomach cancer include:

• loss of appetite
• trouble swallowing
• Tiredness
• unexplained weight loss
• heartburn and indigestion
• Always feeling bloated and gassy after eating
• Feeling full even after eating a small meal or snack

What are the risk factors for stomach cancer?

According to Dr. Saxena, some modifiable risk factors include:

• smoking
• processed food
• smoked food or meat
• physical inactivity
• Liquor
• obesity

Other non-modifiable risk factors are:

• age
• family history
• pernicious Anaemia
• H. pylori Infection
• genetic predisposition

Get the latest news live on Times Now with breaking news and top headlines from around the world.