The digestive process is divided into several stages, each involving different organs.

Once nutrients (carbohydrates, fats, and proteins) are absorbed by the small intestine, the remaining food residue enters the colon. It is in this 1.5-meter-long organ that water is reabsorbed from the intestinal contents, giving stools their solid form.

When water absorption is impaired, excess water is eliminated in the stools, causing them to become loose or liquid.

Diarrhea is not a disease, but a symptom.

It can have multiple causes, including:

  • Chronic inflammatory bowel diseases (IBD) such as ulcerative colitis, Crohn’s disease, and celiac disease.
  • Bacterial, viral, or parasitic infections, which are the most common cause (about 80% of cases), with Escherichia coli being the leading pathogen.
  • Food or drug intolerance.