Patient K

A thirty year old man visits his doctor with a complaint of persistent diarrhea lasting for more than a month. The frequency of his stools is about 3-4 times per day. He came in to see the doctor because he recently noticed bright red blood in one of his stools. He has experienced some abdominal discomfort, but has been drinking plenty of water and is not dehydrated.

Blood in the stool may occur due to inflammation or injury in the GI tract. What does the fact that the blood is “bright red” tell you?


What parts of the colon are found on the left side of the body?


The doctor requests a stool sample for evaluations. The patient reports no recent use of antibiotics and no fever.

The doctor will evaluate the stool for presence of bacteria or bacterial toxins that might be causing infectious colitis. What bacterial infection is associated with recent antibiotic use?


The stool sample is negative for bacteria and bacterial toxins. Blood tests reveal that the patient is not anemic, but he does have a high erythrocyte sedimentation rate (ESR). Increased ESR is indicative of inflammation.

The doctor orders an evaluation by colonoscopy. Colonoscopy involves the use of an endocscope to view the entire length of the colon, all the way to the cecum.

Colonoscopy reveals a uniformly inflamed mucosa in the rectum and sigmoid colon. The mucosa has a granular, reddish appearance, with occasional patches of spontaneous bleeding in shallow ulcerations. A biopsy shows that the inflammation is restricted to the mucosa.

This patient is suffering from one type of inflammatory bowel disease. What type of inflammatory bowel disease does this patient have?


Name the other type of inflammatory bowel disease.


Inflammatory bowel diseases (Crohn's disease and ulcerative colitis) are disorders that are thought to arise due to an inappropriate inflammatory response to the gut microbiota (the naturally occurring bacteria found in the GI tract). In both disorders, there are flares of active disease that alternate with periods of remission in which the patient may be relatively symptom free.

Inflammatory bowel diseases are treated with drugs that suppress the immune system. For mild ulcerative colitis, such as this patient has, the standard treatment to achieve remission is with drugs containing 5-aminosalicylate (5-ASA). 5-ASA works through a variety of mechanisms to suppress inflammation.

This patient is treated with the drug balsalazide, which consists of 5-ASA linked to an inactive carrier molecule. The 5-ASA is not released (and the drug is not active) until the drug gets metabolized in the colon. What do you suppose is responsible for metabolizing balsalazide?


If a patient does not achieve remission with a 5-ASA drug, then he might be treated with glucocorticoids. A newer drug for ulcerative colitis treatment is a sort of topical glucocorticoid treatment for the colon. The glucocorticoid drug is contained in a matrix designed to allow steady release once it reaches the colon. This avoids the side effects associated with systemic use of glucocorticoids. More serious cases of inflammatory bowel disease are treated with biologic therapies such as infliximab, a monoclonal antibody drug that inhibits the action of TNF-alpha.