Cuts
Even the smallest cut in India can become infected. Band-aids do not prevent infection. Immediately clean the wound, and put on an antiseptic. If the cut is large, you may want to consider seeing a doctor. It is best not to wear a Band-aid, which will keep the cut moist and slow healing. It is a good idea to bring a good antiseptic cream from your home country (highly recommended), but Dettol is a good Indian alternative. Observe the healing process closely, and if you see signs of infection, take measures immediately.
Diarrhea
People contract diarrhea for a variety of reasons. If diarrhea is your only symptom, it will often disappear within a few days, especially if you skip a meal or two. Most cases will be gone within forty-eight to seventy-two hours. If diarrhea lasts for more than a week or it is particularly draining, it is best to consult a doctor to ensure that it is not a symptom of a more serious disease Diarrhea is usually caused by food poisoning. It can be caused by bacteria, viruses, amoebas, salmonella, or cholera organisms. Drinking large amounts of water is the most important part of any treatment. Most people should drink at least two or three liters a day.
It is also a good idea to take oral dehydration salts (electrolytes). If there is a severe water loss, electrolytes are highly recommended. A substitute for commercially sold electrolytes is a half-teaspoon of salt and three teaspoons of sugar in a liter of water.
Unless you must take them, antibiotics and other powerful medications should be avoided as often the drug's side-effects are more dangerous than the disease itself (I have personal experience). In some cases, you have no choice but to take antibiotics and such medicines. I read one study that says that streptomycin/sulphatriad (marketed as Streptotriad) was best at curing diarrhea.