Differential Diagnosis for Ribbon Stool

• Single most likely diagnosis
  • Irritable Bowel Syndrome (IBS): This condition is characterized by a change in bowel habits, including the passage of narrow, ribbon-like stools, which is a common symptom in patients with IBS, particularly those with a predominance of constipation (IBS-C).
• Other Likely diagnoses
  • Constipation: Chronic constipation can lead to the formation of hard, narrow stools that may appear ribbon-like due to the prolonged time they spend in the colon, allowing for more water absorption.
  • Anal Fissure: The pain associated with an anal fissure can cause patients to tighten their anal sphincter during defecation, resulting in narrow, ribbon-like stools.
  • Proctitis: Inflammation of the rectum can lead to changes in stool shape and consistency, including the formation of ribbon-like stools, due to the irritation and spasm of the rectal muscles.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Colorectal Cancer: Although less common, colorectal cancer can cause changes in bowel habits, including the passage of narrow, ribbon-like stools, especially if the tumor is obstructing the lumen of the colon.
  • Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can lead to narrowing of the colon (stricture) and subsequent passage of ribbon-like stools, along with other symptoms such as abdominal pain, weight loss, and bloody diarrhea.
• Rare diagnoses
  • Hirschsprung's Disease (in adults): A congenital condition that can present later in life, characterized by the absence of ganglion cells in the distal colon, leading to chronic constipation and potentially ribbon-like stools.
  • Intussusception: A condition where a part of the intestine telescopes into another part, which can cause bowel obstruction and lead to changes in stool shape, including ribbon-like stools, although this is more commonly associated with other symptoms like abdominal pain and bloody stools.