Colitis is a medical condition that refers to the inflammation of the inner lining of your colon (or the large intestine). Numerous factors can lead to colitis, including infections and allergic reactions. When you have colitis, you will feel discomfort and pain in your abdomen. This pain will occur in varying degrees, ranging from mild to sharp pain, recurring over a long period of time.

There are various symptoms of colitis that appear, depending on the type and causes of colitis developed in your body. Some of the symptoms include abdominal pain, cramping, and diarrhea (with or without blood in stool).

Various illnesses and infections can cause inflammation of the colon. Some of the common causes of colitis are as follows.

Infectious colitis
Viruses and bacteria can potentially cause colitis. Most of it is caused by food-borne diseases or food poisoning. Shigella, E-coli, Campylobacter, and Salmonella are the most common bacteria that cause food-borne disease.
These infections are capable of triggering bloody diarrhea and can lead to significant dehydration.
Parasite infections like giardia can possibly cause a significant degree of diarrhea.

Pseudomembranous colitis
It is caused by a bacteria called Clostridium difficile. People who take antibiotics for any infection or have been hospitalized are likely to have this disorder. These antibiotics are responsible for altering the normal presence of the bacteria in the colon and promote the growth of the Clostridium bacteria. Clostridium bacteria produce a toxin that is responsible for causing diarrhea. This condition is actually an infection and often accompanied by fever. In this case, the diarrhea is not bloody at all.

Ischemic Colitis
The arteries that supply blood to the colon are not unlike any other artery present in your body. They also have the tendency to become narrow due to atherosclerosis. This tendency is similar to that of the narrowing blood vessel in the heart, which causes angina or narrowing of blood vessels in the brain, resulting in a stroke. When the colon loses it blood supply due to the narrowing of arteries, it becomes inflamed.
Some mechanical reasons can also be the factor behind the loss of blood supply in the colon. If a bowel twists on itself or an incarnated hernia, it can be one of the possible causes of colitis.
If the blood pressure falls, ischemic colitis occurs and the person is at risk of decreased blood flow to the colon. Blood clots can embolize to block any artery and potentially decrease the blood flow to the bowel.

Inflammatory bowel disease (IBD) and colitis
There are two types of inflammatory bowel disease: ulcerative colitis and Crohn’s disease.

Ulcerative colitis is believed to be an autoimmune illness in which the immunity system of the body starts attacking the colon. Usually, the ulcerative colitis makes its inception in the rectum area and gradually spreads throughout the colon area. The major symptoms of this type of colitis are severe abdominal pain and bloody bowel movements.
Crohn’s disease is a condition that may involve any part of the digestive tract starting from the mouth to the anus. It often has its share of skip lesions, where the diseased area gets interspersed with the healthy areas of the tissues, emerging as one of the major causes of colitis.

Microscopic colitis
Collagenous colitis and lymphocytic colitis are the two diseases that make up this colon inflammation called microscopic colitis. When the colon wall becomes engorged with lymphocytes or collagen, then an inflammation is formed. The most common symptom of this disease is watery, non-bloody diarrhea.
This is not a very common disease and it is seen only amongst older women.

Chemical colitis
Damage and inflammation can occur if any chemical is instilled into the colon. Some harsh chemicals possess the potential to aggravate the inflammation of the mucosal lining of the colon.

Medication-associated colitis
Colitis can be a side effect of some over-the-counter and prescribed medication as well, such as mycophenolate, retinoic acid, ipilimumab and nonsteroidal anti-inflammatory drugs (NSAIDs).

Diarrhea is a common symptom of colitis. Hence. if your diarrhea persists for a longer time period you need to consult a doctor on an immediate basis. Over-the-counter medication might help for some time, but you need to get thoroughly checked by a doctor for a proper treatment of this condition. The fact that there are various causes of colitis and every type requires a different type of treatment makes it essential to visit a doctor on time.