Chronic Diarrhea: Diagnosis and Management

Lawrence R. Schiller; Darrell S. Pardi; Joseph H. Sellin


Clin Gastroenterol Hepatol. 2017;15(2):182-193. 

In This Article

What Is the Utility of Imaging Studies?


18. Imaging studies are useful in some patients with steatorrhea and secretory or inflammatory diarrhea. (1b)

Imaging studies can play an important role in the evaluation of chronic diarrhea by (1) defining anatomic abnormalities such as strictures, fistulae, and diverticula; (2) delineating the degree and extent of inflammation in inflammatory bowel disease (IBD); (3) diagnosing chronic pancreatitis; and (4) demonstrating hormone-secreting tumors. CT enterography and increasingly magnetic resonance (MR) enterography provide detailed small bowel imaging in Crohn's disease.[53] In patients with steatorrhea, abdominal CT or MR scanning, preferably with thin cuts through the pancreas, is useful to assess for chronic pancreatitis or pancreatic malignancy. Plain radiograms of the abdomen with radiopaque markers can be used to evaluate colon transit and the possibility of overflow diarrhea/incontinence.

Hormone-secreting tumors can also be assessed by CT scan, preferably multiphase helical CT or multi-detector CT with thin reconstructions.[54] Imaging with MR may be superior to CT for metastatic disease and tumors in the pancreas, although sensitivity for small tumors such as gastrinomas remains low.[54] Somatostatin receptor scanning has good sensitivity for many hormone subtypes associated with diarrhea[55] and can be used to identify the primary tumor and metastases, monitor treatment response, and select patients for radioreceptor therapy.[56] Positron emission tomography scanning, especially in combination with CT scanning, has become an important imaging modality in the rare patient with hormone-secreting tumors causing diarrhea.[56]