Gut Basics

Also called the colon, the large intestine is about 5 feet long and has distinct functions from the small intestine.

Primary roles:

1. Water Absorption

• Absorbs 1-2 liters of water per day
• Converts liquid chyme into solid stool
• Too much absorption → constipation
• Too little absorption → diarrhea

2. Electrolyte Balance

• Absorbs sodium, chloride, potassium
• Critical for hydration status

3. Bacterial Fermentation

• Home to 100 trillion bacteria (your microbiome)
• Bacteria ferment fiber → produce short-chain fatty acids
• Synthesize vitamin K and some B vitamins

4. Waste Storage & Elimination

• Stores stool in sigmoid colon and rectum
• Controlled release via anal sphincters

Normal bowel movements:

• Frequency: 3 times per day to 3 times per week
• Form: Type 3-4 on Bristol Stool Chart (sausage-shaped, smooth)
• Should not require straining

Common problems:

• IBS (irritable bowel syndrome) → pain, bloating, diarrhea or constipation
• Inflammatory conditions → Crohn's, ulcerative colitis
• Dysbiosis → bacterial imbalance