Foul-smelling poop by itself is not usually a sign of cancer. It most often happens with digestion problems, infections, or trouble absorbing fat. In some cases, cancers that affect how food is digested (especially pancreatic cancer) can lead to oily, pale, foul-smelling stools, but smell alone is not a reliable warning sign.
Pancreatic problems can reduce digestive enzymes and cause fat to pass into the stool, which makes bowel movements greasy, hard to flush, and strong-smelling. Colorectal cancer can change the gut environment, but stool odor isn’t a dependable way to detect it at home.
What matters more than smell are “alarm” signs like blood in the stool or black, tarry stools, unexplained weight loss, belly pain, or a lasting change in bowel habits, like persistent diarrhea or constipation. If these appear, especially together, medical evaluation is important to find the cause early.
This information is for guidance only and doesn’t replace a medical evaluation. If foul-smelling stools persist or emerge with the symptoms above, you should see a family doctor or gastroenterologist for further assessment. Avoid self-medicating, and keep routine checkups and recommended cancer screening up to date.