In this issue, Scheidler and Meiselman report their observations of four patients in whom they used verapamil for the symptomatic treatment of microscopic colitis. 1 Three of the patients had lymphocytic colitis, and one had collagenous colitis; three were women, and one was a man.
All responded dramatically to 180 or 240 mg of verapamil daily. Other therapies had poor to no results controlling the watery diarrhea. Unfortunately, they did not have the opportunity to biopsy their patients after the treatment was successful. We also have to assume that they did not observe other patients with microscopic colitis in whom the verapamil was not successful. After reading this report, one might encourage a trial of verapamil in patients who are responding poorly or not at all to the usual therapies. Usual therapies are mesalamine, bismuth subsalicylate, antibiotics, and, finally, prednisone. 2 Scheidler and Meiselman carefully discuss possible etiologies of microscopic colitis and available therapies. I need not repeat those here.
Of note is the fact that this diagnosis is clearly a histologic, pathologic diagnosis because gross appearance of the colonic mucosa is normal. Histology primarily reveals a lymphocytic infiltrate, which is referred to as lymphocytic colitis and was reported by Read in 1980. 3 A lymphocytic infiltrate in conjunction with a thickening of the subepithelial collagen layer of the lamina propria was first reported by Lindstrom in 1976. 4 Because the collagen deposition can be very spotty and because the lesion is microscopic, the groups in Baltimore and Dallas have reported numerous cases and have studied this clinical entity extensively. They came to a conclusion that the histologic, pathologic entity with or without an increase in collagen is probably the same. 5
Nevertheless, one of our most prominent gastroenterology textbooks still refers to the entity as collagenous or lymphocytic colitis. In reality, the semantics are unimportant. This is a histologic diagnosis, and the clinical picture appears to be the same in both. What is important is that the cause or the phenomena of watery diarrhea with no gross abnormality requires that the clinician do the appropriate biopsy surveillance at the time of colonoscopy. We have no good studies that indicate the prevalence or incidence of this phenomenon. There is no question in my mind that, all-too-often, good surveillance biopsies are not done in a patient that has a normal-appearing mucosa in colonoscopy, and the patient is labeled as having an irritable bowel syndrome. The clinical message here is that surveillance biopsy should be done in any patient that has watery, recurrent diarrhea.
The use of a calcium channel blocker to treat diarrhea in clinical situations certainly warrants further study. As the authors specifically point out, the use of verapamil in the treatment of lymphocytic and collagenous colitis warrants more study. In the report published in this issue are observations that need to be substantiated but that certainly are interesting at this point in time.
1. Scheidler MD, Meiselman M. Use of verapamil for the symptomatic treatment of microscopic colitis. J Clin Gastroenterol 2001; 32:351–2.
2. Sartor RB, Murphy ME, Rydzak E. Miscellaneous inflammatory and structural disorders of the colon. In: Yamada T, Alpers D, Laine L, et al., eds. Textbook of gastroenterology,
3rd ed. Philadelphia: Lippincott Williams & Wilkins, 1999:1857–83.
3. Read NW, Krejs GJ, Read MG, et al. Chronic diarrhea of unknown origin. Gastroenterology 1980; 68:264–70.
4. Lindstrom CG. “Collagenous colitis” with watery diarrhea. A new entity. Pathol Eur 1976; 11:87–91.
5. Jessurun J, Yardley JH, Lee EL, et al. Microscopic and collagenous colitis: different names for the same condition? Gastroenterology 1986; 91:1583–4.