Most people rarely think about what is normal for their own bowel movements until something changes. Doctors say certain shifts in colour, texture or frequency can be an early sign that something needs medical attention, while others are harmless and linked to diet or medicines. Understanding the difference may help people with digestive symptoms know when to seek advice.
What Counts as Normal Varies by Person
According to retired gastroenterologist M. Nuri Kalkay, bowel habits differ from person to person depending on diet, activity levels, how much water someone drinks and any medicines they take. Because of this, the most useful warning sign is often a change from what is usual for you, rather than matching a single fixed description of “normal.”
Changes That May Need Urgent Attention
Black or Tarry Stools
Surgeon Jeffery M. Nelson, of Mercy Medical Center in Baltimore, said stools that are truly black, rather than simply dark brown, can point to bleeding higher up in the digestive system, such as in the stomach or the upper part of the small bowel. Iron supplements or bismuth-based medicines can also darken stools, so it is worth checking with a doctor if the cause is unclear.
Bright Red Blood
Blood seen on toilet paper, in the toilet water or mixed through the stool usually comes from lower down, such as the back passage or rectum. Nelson said causes can include piles, small tears, growths called polyps, or in some cases rectal cancer. Any of these findings should be checked by a doctor.
Maroon-Coloured Stools
Darker, maroon-toned stools that are looser and have an unusually strong smell may suggest bleeding further up in the bowel, according to Nelson. He said this pattern is often linked to pouches in the bowel wall called diverticula, or abnormal blood vessels, and is a reason to seek emergency care.
Changes That May Need Medical Review
Pale, Oily or Strong-Smelling Stools
Internal medicine doctor Chris Carrubba said pale, oily stools with a particularly unpleasant smell can mean the body is struggling to absorb fat properly. This can occur with problems affecting the pancreas, liver or bile system, and may increase the risk of low levels of certain vitamins over time.
Changes in Shape or Consistency
A lasting change from your usual stool shape, such as becoming much narrower, may be linked to inflammation in the bowel or an infection, said surgeon Karen Soika. A shift towards watery stools can be associated with irritable bowel syndrome, infection or inflammatory bowel disease.
Mucus in the Stool
Some mucus can be normal, but gastroenterologist Peyton Berookim said noticeable amounts are often linked to inflammation in the bowel, including conditions such as ulcerative colitis or Crohn’s disease. Mucus alongside blood or stomach pain should not be ignored.
Persistent or Frequent Diarrhoea
Gastroenterologist Jack Braha said short-term diarrhoea after an infection is common, but episodes lasting more than two weeks, or accompanied by bleeding, weight loss or night-time symptoms, need medical review. Possible causes include lactose intolerance, irritable bowel syndrome, coeliac disease or inflammatory bowel disease.
Hard or Infrequent Stools
Constipation is usually linked to low fibre or fluid intake, but can also be caused by medicines or, less commonly, a blockage or bowel cancer. Braha said symptoms starting after age 50, or not improving with simple changes, may warrant further tests such as a colonoscopy.
Diarrhoea After Travel or Water Exposure
Carrubba said watery diarrhoea following contact with untreated lake or stream water may be due to a parasite called giardia, which can also spread through unwashed produce or poor hand hygiene. This can usually be treated once identified.
Why This Matters
Bowel symptoms are often harmless, but they can occasionally be an early signal of inflammation, infection or, less commonly, more serious conditions. Recognising a meaningful change from your own normal pattern may help people seek timely advice rather than waiting until symptoms become severe.
What to Keep in Mind
- These descriptions are general guidance, not a diagnosis.
- Some causes, such as iron supplements or certain medicines, are harmless.
- Persistent, severe or unusual symptoms should always be discussed with a doctor.
- Symptoms and underlying bowel inflammation are not always the same thing, so testing may be needed to understand the cause.
Reference
Original source: “If Your Poop Looks Like This, It’s Time To See A Doctor,” HuffPost, 17 October 2026. This article is based on expert commentary gathered by HuffPost and does not report on a specific peer-reviewed study.
This article is a journalistic summary for informational purposes only. It does not constitute clinical advice or a recommendation to alter treatment decisions.