How long does it take my food to digest? That depends on a lot of factors, depending on the food types we eat, and medications we might be taking to decrease our stomach acid.
The pH of your stomach is 1.5 to 3.5, because your stomach excretes about 1.5 liters of gastric acid daily.
Fat takes longer to leave the stomach than other foods, sometimes remaining in the stomach for up to six hours. Remember a big meal of a double burger and fries? You feel full for a very long time.
Liquids take around 20-30 minutes to exit the stomach. Water and liquids do fill you up, but that effect doesn’t last very long. Complex carbohydrates break down at a slower rate than simple carbohydrates. Proteins take about 1.5 hours to leave the stomach.
Usually, most of a regular-sized meal empties from the stomach within two hours. After that it takes about 6 hours to pass through the small intestine, where bicarbonate is added to the mix to bring the pH to a more neutral 7. Your small intestine as around 22.5 feet long and about 1.5 inches wide. Food enters the large intestine, which is around 5 feet long, for more digestion and absorption of water and essential vitamins. Undigested material gets pushed toward the anus for elimination. It takes an average of 33 hours (almost 1.5 days) for foods to reach from the mouth to the anus.
Once it gets to the end, for elimination our stools can be graded for texture and even color depending on medications being taken:
Bristol Stool Scale: is a scale that gastroenterologists use to “classify” our feces. Feel free to see the Bristol Stool Scale charts on-line!
- Type 1: Separate hard lumps, nut-like in appearance
- Type 2: Sausage-shaped, but lumpy
- Type 3: Like a sausage but with cracks on its surface
- Type 4: Like a sausage or snake, smooth and soft. (most normal stool)
- Type 5: Soft blobs with clear cut edge
- Type 6: Fluffy pieces with ragged edges, a mushy stool
- Type 7: Watery, no solid pieces, entirely liquid
Medications that can affect the color of our stools (feces)
|black||Iron, charcoal, bismuth (PeptoBismol)|
|Red or orange||phenazopyridine, rifabutin, rifampin, or antacids with aluminum. Cefdinir interacts with iron in baby formulas, and breast milk|
|White speckled||Antacids with aluminum|
|Yellow||Alli (orlistat) or anything that inhibits fat absorption|
|Green||Chlorophyll, iron or drugs causing diarrhea (antibiotics, laxatives)|
|Red or black tarry stools||GI bleeding due to aspirin, drugs like Motrin/Aleve, antiplatelet drugs like Plavix, or anticoagulants like warfarin or Xarelto & Eliquis|
|Pale stools||Liver injury from hepatoxic drugs|
Many times our patients are prescribed potassium tablets, and they occasionally see the ghost tablets in their toilet. This is OK, because you are seeing leftover was, after the potassium leaches out. Any time you have a question about anything, including your bowels, your Thompson Pharmacist is the best resource. Go ahead and ASK! At Thompson Pharmacy it’s all for you!
Tomorrow morning when you flush the toilet, you will have a greater appreciation for your gastrointestinal tract! Next week we will start covering laxatives.