Here's a piece on the topic that I wrote for the Mar '02 issue of "Undercurrent"
http://www.undercurrent.org/
"Diarrhea and Divers: How to avoid hourly toilet breaks
Stomach problems can wreck dive vacations, as many of our readers can attest. For example, Tina Peterson and her husband (Omaha, NE) visited Coco View on Roatan last September. She wrote, The worst part about our vacation was that we got diarrhea . We were not the only ones. Literally half of the guests were sick part or all of the week. We did not drink the water (although we were told it was safe). I assume it was the water the kitchen was cooking with that made us ill. It really sucked being sick on vacation. My husband missed two days of diving, and I missed one day. A few people on the resort only got in a few dives the entire week. The resort has a limited selection of medications, and all of the stomach meds were gone two days after we arrived.
Hal Koch, MD, reported at an Underwater Hyperbaric Medicine conference, Much of the world has mostly contaminated drinking water. The World Health Organization started a program of providing clean and safe drinking water for developing countries at a cost of one billion U.S. dollars. The program was a total failure due to civil strife, wars, and refugee movements. In essence, you cannot go outside North America or Western Europe and expect to have safe drinking water. With that in mind, we asked Doc Vikingo to describe what you can do to avoid hourly toilet duty on your next dive vacation.
Whether you call it La Turista , Delhi Belly, Tiki Trots, or Montezuma's Revenge, its usually not life-threatening. But its always unpleasant and inconvenientespecially if you get hit while underwater. Typical signs and symptoms include the rapid development of diarrhea, nausea, bloating, cramping, and weakness. Despite all its sobriquets, travelers diarrhea (TD) is largely the result of just a few microbial culprits. More than 80 percent of the cases result from ingesting liquids and foods contaminated by either human or animal fecal matter. TD is usually caused by bacteria, but it can also be brought on by parasites and viruses. Although not related to infection, diarrhea can also result from greasy, fatty, and spicy foods, items you are not used to, or just excessive vacation consumption.
The chances of contracting TD at a dive venue depend mostly on the degree of development of the location. For example, the odds of contracting TD increase as you travel from the U.S. to the Caribbean, or Latin America to Southeast Asia.
The CDCs Travelers Health Web site (
http:// www.cdc.gov/travel/) is a good source for assessing the risk of various locations.
Whats a Body to Do?
You can avoid most gastrointestinal illness by being cautious about food and drink and by frequently washing your hands. While most travelers focus on ensuring the fluids they drink are pure, food-borne pathogens are the number one cause of infection. Eat only fruits and vegetables that have been thoroughly cooked, or at least peeled and cleaned. Shy away from leafy greens that are difficult to wash thoroughly. Stick with recently and well-cooked items served very hot. Avoid raw foods such as seviche and shellfish, and undercooked meat or fish. Pass on the street vendors and eateries that appear unhygienic.
Major resorts and restaurants in higher risk areas often use purified tap water or serve bottled water. Live-aboards with properly maintained desalinization systems produce potable water. If in doubt, ask. And dont forget to ask about the ice in your drinks. Bottled beverages like soda are generally safe, but avoid products like milk and beer if they are not pasteurized, and fresh fruit juices sold at roadside stands. I have heard divers say that adding lime or spirits to what one drinks offers protection. Poppycock. They may make drinks tastier & more fun, but that s about it.
When Basic Preventive Measures Dont Work
Given a compelling need to take a preventive medication, Pepto-Bismol is often the product of choice. It helps about 65 percent of the time when taken four times daily, beginning several days before traveling. However, it shouldnt be used for more than three weeks and people with aspirin sensitivity, kidney disease, or those taking blood thinners should avoid it.
Antibiotics such as Cipro, Bactrim, or Septra have a 70-95 percent efficacy taken once a day. They should only be considered for high-risk, short-term travelers whom severe diarrhea may seriously harm (e.g., persons with chronic kidney failure or insulin dependent diabetes). If the cause of your diarrhea is something other than the bacteria targeted by the antibiotic or a resistant bacterial strain, the drugs will simply make things worse.
Treatment
Most often the illness will be self-limiting and can be treated with Pepto-Bismol. However, if you have a bloody stool, high fever, severe abdominal pain, or persistent vomiting seek immediate medical help. If the condition doesnt abate after a couple of days, or resolves and then returns, see a doctor. The over-the-counter antidiarrheal Imodium controls diarrhea, although it should be used judiciously as it can prolong the illness while controlling some symptoms. It is best used as an adjunct to antibiotics. Lomotil requires a prescription and often is not recommended for bacterial diarrhea due to possible adverse effects on the large intestine. Before traveling, discuss the issue with your physician and get appropriate prescriptions. Antibiotics may be prescribed with the same precautions noted in the prevention section above.
Although antibiotics are often available over the counter in foreign countries, this should not encourage self-treatment. Besides the risk that you may choose the wrong drug for the bug you have, these drugs can cause severe or fatal allergic reactions. Some, also, cause sensitivity to the sun, which can occasionally be extreme.
Additional Steps
Fluid loss from diarrhea can increase a divers susceptibility to DCS. In addition, Lomotil and Imodium can be drying, and many antibiotics are best accompanied by liberal amounts of water. If you get ill, drink copious amounts of water, sports drinks, or clear, salty broth. Avoid caffeinated beverages, dairy products, and prune, apple, and orange juices. Signs of worrisome dehydration include extreme thirst, dry mouth, passing reduced amounts or dark yellow urine, dizziness, cramping in the extremities, and warm, dry skin.
If you develop any of these, seek prompt medical attention. Start yourself on an oral rehydration solution such as Rehydralyte or Pedialyte. Or, produce your own by mixing one teaspoon of salt and eight teaspoons of sugar in a quart of purified water, making a fresh solution every 24 hours.
An episode of TD forces a day in bed in about 20 percent of the cases. It should go without saying that if you dont feel well enough to dive safely and comfortably-- dont. ----Doc Vikingo'
Hope this proves helpful.
DocVikigo