Showing posts with label IBS. Show all posts
Showing posts with label IBS. Show all posts

Thursday, October 15, 2009

The Mechanics of Digestion

Once we swallow a bite of food, a pill, or slurp a smoothie, the ride begins - as food has to travel down the 30 feet (9 meters) pathway before all is said and done. Fortunately, muscle tone in our organs shortens that length by about half.

Digestion begins in the brain that sends messages to a system of salivary glands. Mechanical digestion
starts in the mouth: My Pink Elephant Still Smells Like Rotten Apples. Starting from Mouth to Pharynz to Esophagus to Stomach to Small Intestine to Large Intestine to Rectum to Anus.

The first part of swallowing is a
flinging back of the food into the upper part of the esophagus by a backward movement of the tongue. This powerful motion is followed by wave-like movements in the distal segments of the gullet, which empty remaining bits of food into the stomach. Mechanical movements of the esophagus, stomach, and intestine keep food passing through the digestive system. The normal movements of the small intestine are rhythmical segmentation, or swaying and pendular, or a peristaltic rush. In the stomach the movement is also peristaltic, kneading and mixing take place only in the strong-muscled pars pylorica. The pylorus does not wait to open until the food is digested. Fluids run out as soon as they are drunk, but solids are being held back until the stomach has a chance to liquefy them. The colon is a sluggish organ with few and slow movements, but a few times a day there are mass movements which carry material usually from the transverse colon over into the sigmoid. These movements may give rise to the final act of digestion, letting organisms eliminate waste from the GI tract.

Healthy peristalsis will let you drink a glass of water while standing on your head, although if not skilled enough it could come out of your nose. Astronauts claim that they do not have any problems digesting food with zero gravity.
The mechanics of the digestive tract can, indeed, be affected by the accessory organs - salivatory glands, pancreas, liver, and gallbladder, enzymes and small molecules helping to digest food.
Reverse peristalsis, vomiting, constipation, delay in absorption, leaky gut, intestinal gases caused by fermentation and by irritating foods, may all upset the gradient.

If you tend to have digestive problems, you may need to lie down at least two hours after you finish a meal, this seems to help some people. It does not work for many others though.
In general, your best bet for maximum digestive efficiency seems to be sitting upright. The Mayo Clinic also suggests that you make sure you're relaxed while you're eating, so that your digestive muscles contract normally.

Digestion time also varies depending on the individual and the type of meal. For healthy adults, it's usually between 24 and 72 hours. After you eat, it takes about six to eight hours for food to pass through your stomach and small intestine. Food then enters your large intestine (colon) for further digestion and absorption of water. Elimination of undigested food residue through the large intestine usually begins after 24 hours. Complete elimination from the body may take several days.
Heartburn - a feeling that food is stack in the throat - is one of digestive problems that is usually made worse by lying down or bending over while eating. It gets better if you sit or stand up.

This happens when food and stomach juices go back into the esophagus. Common causes of this (gastroesophageal reflux or GERD) include:

  • Anatomical abnormalities such as

o incomplete closing of the valve (the lower esophageal sphincter, or LES) between the esophagus and the stomach,
o
hiatal hernia, which occurs when a small portion of the stomach pushes upward through the diaphragm, which is the muscle that separates the lungs from the abdomen.

  • Pressure on the stomach caused by obesity, frequent bending over and lifting, tight clothes, straining with bowel movements, vigorous exercise, and pregnancy.
  • Smoking
  • Stress, which can increase the amount of acid your stomach makes and cause your stomach to empty more slowly.

Common foods that can worsen reflux symptoms include

  • Citrus fruits
  • Chocolate
  • Drinks with caffeine or alcohol
  • Fatty and fried foods
  • Garlic and onions
  • Mint flavorings
  • Spicy foods
  • Tomato-based foods, like spaghetti sauce, salsa, chili, and pizza

Use of prescription and nonprescription medicines, such as aspirin, ibuprofen, prednisone, iron, potassium, antihistamines, or sleeping pills is also one of common causes.




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Thursday, May 7, 2009

IBS Resources

Mirrored from Aurametrix

IBS is a disorder of heterogeneous pathophysiology for which there are no good diagnostic tests nor effective treatments (online study on unmet needs conducted by IFFGD and UNC). Existing tests are performed to exclude diseases such as IBD, colorectal cancer, diseases associated with malabsorption, systemic hormonal disturbances, and enteric infections.
Routine serologic screening for celiac sprue in patients with IBS-D or IBS-M may be useful.
Lactose intolerance can cause IBS-D, intolerances to other food groups such as

Percentage of population with IBS reported in ...Image via Wikipedia

fructose could be also implicated. Problems with serotonin signaling, or the transmission of messages between the nerves, can lead to IBS-C

The guidelines, issued by the American College of Gastroenterology were published in the January2009 issue of The American Journal of Gastroenterology.

Most IBS treatments relieve symptoms rather than resolve the condition itself.

The new guidelines encompass existing evidence on conventional treatments for IBS as well as new therapies (probiotics, for example) and alternative therapies (acupuncture and more).

Fiber products -- including psyllium, anti-spasmodic medications and peppermint oil -- may be effective in some people. "The evidence is poor, but some patients say they feel better,"

More data is needed on probiotics, live microorganisms (usually bacteria) similar to the "good" organisms found normally in the gut. The dichotomous data suggest that all probiotic
therapies have a trend for being efficacious in IBS, whereas the
continuous data indicate that Lactobacilli have no impact on
symptoms; probiotic combinations improve symptoms; and
there is a trend for Bi fidobacteria to improve IBS symptoms.Researchers and practitioners still need to figure out the species of bacteria used, how many species, and dosages.

Non-absorbable antibiotics -- those targeted to the gut only, such as rifaximin (Xifaxan) -- also seem to help some people, especially those who have "diarrhea-predominant IBS."

Selective C-2 chloride channel activators, notably lubiprostone (Amitiza), are effective for "constipation-predominant IBS."
5HT 3 antagonists such as alosetron (Lotronex) relieve symptoms of diarrhea but can cause constipation and colon ischemia, a restriction of blood flow.
5HT 4 agonists, though effective against constipation, are not available in North America because of a heightened risk of cardiovascular problems.

There is yet to be conclusive evidence on Chinese herbal mixtures, and the mixtures run the risk of causing liver failure and other problems. Differences in the content of compounds and the purity of ingredients complicate evaluation of benefits.

Similarly, the evidence on acupuncture remains inconclusive.

There is no evidence at this point that testing for food allergies or following diets that exclude certain foods alleviates IBS symptoms.

Routine diagnostic testing for IBS is not recommended, although some testing should be performed in certain subgroups of patients.

More about IBS at the U.S. National Institute of Diabetes and Digestive and Kidney Diseases site.


To ease IBS with diarrhea, avoid fried foods, too much fiber, especially insoluble such as apple skins, chocolate, alcohol, caffeine, carbonated drinks, the artificial sweetener sorbitol (found in sugarless gum and mints), and fructose (the simple sugar found in honey and many fruits). These can worsen diarrhea symptoms. Drink six to eight glasses of plain water a day - not with meals, but an hour before or an hour after meals. Avoid drinking hot teas.

To ease IBS with constipation, drink water and exclude beverages as suggested above. Eat small frequent meals and be careful with fiber. Soluble is better at reducing severety of symptoms, as was shown in this 2005-2007 clinical trial, but all types of fiber could potentially worsen the syndrome. You may also want to exclude broccoli and other dark green vegetables from your diet. Keep an IBS symptom journal, it would help you and your doctor to find what foods and situations trigger your IBS symptoms.

Not Censored IBS Diet Links:

More Links:


International Foundation for Functional Gastrointestinal Disorders (IFFGD) sites:
Chronic Constipation aboutConstipation.org
Acid Reflux Disease (GERD) aboutGERD.org
Motility Disorders aboutGImotility.org
Irritable Bowel Syndrome (IBS) aboutIBS.org
IAMIBS.org
Incontinence or Urgency aboutIncontinence.org
Digestive Disorders in Kids
and Teens
aboutKidsGI.org
Digestive Health Research giResearch.org
Participate in IBS survey


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