Colitis is an inflammation of the inner lining of the large intestine, says MedicineNet. One symptom is intermittent cramps in the lower abdomen that can lead to watery diarrhea. The pain worsens just before the episode of diarrhea and then subsides afterwards for a time.
Inflammation and deterioration of the lining of the large intestine might also produce blood in the stool, according to MedicineNet. In the ulcerative type of colitis, bleeding ulcers form on the wall of the large intestine.
Besides the diarrhea and pain, the patient may also experience a general ill feeling, fever and chills, dehydration and tiredness. The patient may constantly feel like he needs to move his bowels, claims MedlinePlus. If the patient is dehydrated, he may also be lightheaded, weak and producing less urine than normal. His eyes and mouth may also be dry.
Causes of colitis can be a viral or parasitic infection or bacteria food poisoning, says MedlinePlus. It can also be caused by ulcerative colitis, Crohn's disease or insufficient blood flow to the colon. Some people develop colitis after they've received radiation treatment to the large intestine.
Colitis can be diagnosed through a sigmoidoscopy or colonoscopy, where a flexible tube attached to a tiny camera is inserted into the large intestine, according ro MedlinePlus.