" The severity of gut dysfunction varies for four reasons: The toxic organisms present may be beyond what the Clean Gut program is designed to remove. These include severe yeast overgrowth, parasites, viruses, and certain bad bacteria, such as salmonella, Escherichia coli (E. coli), or Clostridium difficile (C. difficile). Other influences may cause a severe leaky gut, such as heavy-metal toxicity or full-blown autoimmune-induced inflammation, including Crohn’s disease and ulcerative colitis, which impair the regeneration of the cells of the intestinal wall. Mechanical obstructions may interfere, such as constrictions, scarring, or an impacted, dilated colon. Diverticulitis may be present, with pockets of infection. Of these four reasons, only the final two require immediate medical attention and surgery. "

― Alejandro Junger , Clean Gut: The Breakthrough Plan for Eliminating the Root Cause of Disease and Revolutionizing Your Health