Impaction of the stomach typically consists ofexcessive dry, fibrous ingesta, but may also be composed of ingested materialsthat form a mass, such as persimmon seeds or mesquite beans.1-3 Otherfeeds that tend to swell after ingestion, including wheat, barley, and sugarbeet pulp, may also cause impaction. Additional signs may include dysphagia,dropping of feed, and bruxism.3,5 However, the diagnosis of stomachimpaction is usually made at surgery on horses that have had uncontrollablecolic or poor response to medical therapy. However, endoscopy will revealgastric impaction, and may provide information on the specific nature of theimpaction. Although this would not typically be performed on an acute coliccase, it would be indicated in a horse with chronic colic.