Section: USMLE

14) A 25-year-old man presents to a rheumatologist with complaints of joint pain involving the large joints of the legs. On questioning, the patient indicates that exacerbations in the joint pain are frequently accompanied by diarrhea. Which of the following is the most likely diagnosis?

1. Amebic colitis
2. Chronic appendicitis
3. Diverticulosis
4. Pseudomembranous colitis
5. Ulcerative colitis

Several gastrointestinal diseases are associated with rheumatologic complaints. The most frequent of these are the chronic inflammatory bowel diseases, ulcerative colitis, and Crohn disease, which can be associated with sacroiliitis (related to HLA-B27) or lower limb arthritis. Other gastrointestinal diseases associated with arthropathy include bypass surgery, Whipple disease, Behcet syndrome, and celiac disease.

Amebic colitis is caused by ingestion of infectious cysts (typically from Entamoeba histolytica). Symptoms include abdominal pain and diarrhea; malaise and weight loss also may occur. Cecal amebiasis can resemble acute appendicitis.

Chronic appendicitis may be asymptomatic or cause poorly defined abdominal pain.

Diverticulosis is usually a disease of older adults. It is often asymptomatic unless inflammation supervenes.

Pseudomembranous colitis is a severe form of diarrhea usually seen in the setting of prior antibiotic use. The causative organism is almost always Clostridium difficile.