Jeffery Nelson, M.D., FACS, FASCRS, is an experienced colorectal surgeon who serves as Surgical Director of The Center for Inflammatory Bowel and Colorectal Diseases, The Institute for Digestive Health & Liver Disease at Mercy.

Dr. Jeffery Nelson has more than 25 years of experience in Colon and Rectal Surgery. His areas of interest include colorectal cancer, rectal bleeding, hemorrhoidectomy and diverticulitis. He brings special expertise in such areas as rectal prolapse, ulcerative colitis and complex anal pathology. Dr. Nelson is board certified in two specialties, General Surgery and Colon Rectal Surgery.

He offers insight on what the color of one’s stool may indicate about health and how to tell if it is time to see a doctor. 

  • Black and/or tarry - this is like the color black, not just dark brown.  This means bleeding is happening from an upper GI source like the esophagus, stomach or small bowel.  See a doctor or go the Emergency Department (ED) right away. 
  • Bright red blood - either by itself on the toilet paper, in the water, or streaked on the stools.  This indicates a bleeding source from the anal canal or a low rectal source.  Things like internal hemorrhoids, anal fissures, rectal polyps, or rectal cancers can all do this.  All these are reasons to see a doctor.
  • Maroon stool - this is usually quite liquid and has a very unpleasant and distinct odor.  This indicates bleeding from the very end of the small bowel or the colon.  Diverticulosis and arteriovenous malformations are the classic causes of this presentation.  Go to the ED right away.

All of the above presentations typically mandate either upper endoscopycolonoscopy or both - maybe urgently (an emergency scenario). 

  • Hard, pellet like stools alternating with watery diarrhea, or loose stool, along with mucous can indicate irritable bowel syndrome (IBS), but this is a diagnosis of exclusion and typically also requires endoscopy to rule out colorectal cancer or polyps.  Change in bowel habit is a common presentation of colorectal cancer.
  • Persistent watery diarrhea may also just be IBS, but can also be from a microscopic colitis.  Once again, endoscopy is necessary.