Obstipation unresponsive to usual therapeutic maneuvers

Diagnosis: Fecal impaction caused by a proctophytobezoar

CT imaging revealed a proctophytobezoar. On follow-up questioning, the patient recalled consuming approximately 10 ounces of cooked quinoa, a nutritious, gluten-free, high-protein seed, just prior to the onset of her constipation.

Constipation disproportionately affects the elderly and the young.¹ Fecal impaction is a sequelae of constipation. Most commonly defined as hard, compacted feces in the rectum, fecal impaction can also include more proximal impactions due to fecal loading or retention.²

Causes of constipation and fecal impaction are similar and include low intake of dietary fiber, dehydration, immobility, alcohol ingestion, laxative abuse, medication adverse effects, depression, dementia, spinal cord dysfunction, diabetes, metabolic imbalances, and hypothyroidism.^2,3 Insufficient hydration with consumption of a high-fiber food, as in this case, or with a bulk-forming laxative such as psyllium seed can result in fecal impaction.³

The many causes of a bezoar
A bezoar is a mass of poorly digested material that forms within the gastrointestinal tract—usually in the stomach—and less commonly in the small or large intestine.⁴ Trichobezoars (hair), lactobezoars (milk curd), phytobezoars (plant fiber), medication bezoars, and lithobezoars (small stones, pebbles, or gravel) are named after their contents. In keeping with this naming tradition, a gummi bear bezoar⁵ has also been described. Fecal impaction due to phytobezoars primarily composed of seeds has been associated with prickly pears, watermelons, sunflowers, pumpkins, pomegranates,^6,7 and sesame seeds.⁴ Our patient’s experience adds quinoa seeds to this list.

Patients will complain of nausea and rectal urgency
Patients with fecal impaction may complain of nausea, rectal urgency, and rectalgia. A ball-valve effect of the fecal mass may allow paradoxical fecal incontinence and diarrhea.³ Digital rectal exam may demonstrate stool of any consistency, from rock hard pellets to soft clay-like stool.³ Absence of stool in the rectal vault does not rule out fecal impaction, and more proximal impactions may be revealed on plain abdominal radiography as bubbly, speckled masses of stool with associated signs of obstruction, such as colonic dilatation.

Fever, increased leukocyte count, and abdominal tenderness may indicate colonic perforation or ulceration. Signs of generalized peritonitis and free air on abdominal radiography warrant an immediate surgical consult.³