MSI Press Blog

  The color of poop - a visual guide to the quiet warnings our bodies send 🟥 Red Possible cancers: • Colon cancer • Rectal cancer • Anal cancer Why it happens: Fresh blood mixes with stool when tumors in the lower GI tract bleed. Clue: Blood is on the stool or in the toilet bowl, not digested into it. ⚫ Black / Tarry Possible cancers: • Stomach cancer • Esophageal cancer • Small intestine tumors Why it happens: Blood from higher up in the GI tract gets digested, turning stool black and sticky. Clue: Looks like coffee grounds mixed with tar. 🟤 Dark Brown / Maroon Possible cancers: • Right‑sided colon cancer • Small bowel tumors Why it happens: Slow bleeding higher in the colon darkens stool without turning it fully black. Clue: Often overlooked because it still “looks like poop.” 🟡 Yellow / Greasy / Floating Possible cancers: • Pancreatic cancer • Ampullary cancer Why it happens: Tumors block pancreatic enzymes → fat isn’t digested → stool becomes oily, pale, ...

  Poop is one of the body’s earliest alarm systems, and different cancers can alter stool in different ways. Pencil‑thin stool is the classic red flag for colon cancer, but it’s far from the only pattern worth knowing about. The changes below come from how tumors block, bleed, or interfere with digestion and bile flow. 1. Colon & Rectal Cancer Why stool changes: Tumors narrow the passageway, bleed easily, or disrupt water absorption. Key stool patterns: Pencil‑thin or ribbon‑thin stool — narrowing from a tumor blocking the lumen. Pebble‑like hard pellets — obstruction causing excess water absorption. Blood in stool Bright red → lower colon or rectum. Black/tarry → bleeding higher up. Mucus in stool — especially with mucinous tumors. Alternating constipation and diarrhea — partial obstruction. 2. Pancreatic Cancer Why stool changes: Blocked bile duct → no bile reaching the intestine; lack of pancreatic enzymes → fat malabsorption. Key stool patterns: P...