When possible, patients taking nonsteroidal anti-inflammatory medications should discontinue them when the diagnosis of
microscopic colitis is made. Although there is no direct evidence of its efficacy, a trial of elimination of
caffeine or
lactose or both should be undertaken. Nonspecific
antidiarrheal agents (eg,
loperamide,
diphenoxylate) may be administered, but appear to be largely ineffective in this population. An aminosalicylate should be initiated at full therapeutic dose (2 to 4 g daily) as the first-line
therapy. Because
sulfasalazine appears to be associated with a high incidence of adverse effects in patients with
microscopic colitis, other derivatives of
5-aminosalicylate (5-ASA) are preferred.
Bile salt-binding agents such as
cholestyramine or
colestipol appear to be effective alternatives for patients who are either unresponsive to or intolerant of aminosalicylates. Systemic
corticosteroids are an effective treatment for
microscopic colitis, but may offer only transient improvement in symptoms. Given their potential adverse effects,
corticosteroids should be reserved for patients with refractory disease in whom aminosalicylates and
bile salt-binding agents have failed. Other agents that may be effective include
antibiotics,
bismuth subsalicylate,
budesonide,
pentoxifylline,
octreotide, and
methotrexate. Although these agents can be considered in unusual cases, the cumulative clinical experience with them in this setting is relatively limited. Surgical intervention, with either fecal stream diversion or subtotal
colectomy, shows promise as an intervention of last resort. In refractory cases of
microscopic colitis, strong consideration should be given to excluding a concomitant diagnosis of
celiac disease, bacterial overgrowth, or
chronic infection.