Are Red Stools after Red Dragon Fruit (Selenicereus costaricensis) Ingestion a Red Herring? – Case Report and Clinical Pearls for Recognition

Are Red Stools after Red Dragon Fruit (Selenicereus costaricensis) Ingestion a Red Herring? – Case Report and Clinical Pearls for Recognition

Are Red Stools after Red Dragon Fruit (Selenicereus costaricensis) Ingestion a Red Herring? – Case Report and Clinical Pearls for Recognition

Haematochezia is the most common presentation of lower gastrointestinal bleeding and is a frequent diagnosis resulting in admission or outpatient attendance to gastroenterology and colorectal services. Common causes of per rectal bleeding include diverticular bleeding, hemorrhoids, colorectal malignancy, colonic and rectal polyps, colitis, inflammatory bowel disease, anal fissures, and vascular malformations [1,2]. Less common causes include hemorrhagic enteritis, bacterial or amoebic dysentery, vasculitides such as Henoch-Schonlein purpura, intestinal amyloidosis, and blood dyscrasias such as hemophilia or leukemia [3]. Known mimics of haematochezia with red discoloration of stool include ingestion of beets, red food coloring, cherry syrup, and medications such as cefdinir or rifampicin [3,4].

About half of patients with per rectal bleeding presenting to the emergency department are admitted, and 80% of lower gastrointestinal bleeding stops spontaneously. Overall mortality ranges from 2% to 4%, and the mean length of stay for admitted patients varies from 5.4 days to 7.2 days [1,2,5].

The red dragon fruit (Selenicereus costaricensis, previously Hyloreus costaricensis), also known as the Costa Rican pitaya fruit, belongs to the climbing Cactaceae family and most often takes on an oval shape (Figure 1). Several varieties of dragon fruit are grown – the pulp of the fruit may be red or white in color, and the skin can be red or yellow. The seeds of the fruit resemble that of the kiwifruit and are embedded within the fruit pulp [6].

The dragon fruit is cultivated and consumed worldwide due to its sweet flavor and increasing interest in pharmaco-therapeutic benefits as a “wonder fruit” [6,7]. The postulated activity of the fruit’s phytoconstituents includes nutraceutical (vitamins B1, B2, B3, and C), anti-oxidant (gallic acid, vanillic acid, syringic acid, protocatechuic acid, p-hydroxybenzoic acid, p-coumaric acid, lycopene, β-carotene), anti-microbial (betacyanin), anti-cancer (β-amyrin, β-sitosterol, stigmast-4-en-3-one) and anti-diabetic effects (flavonoids) [6-12]. In addition, Pitaya fruits are rich in micronutrients such as calcium and zinc while also containing high concentrations of betacyanin within the pulp and peel of the fruit [6].

To the authors’ knowledge, this is the first case report documenting hospital admission with a benign presentation of blood-red stools following red dragon fruit ingestion. We review the available literature regarding the fruit and betacyanins and offer clinical pearls to aid in differentiating this benign occurrence from more common and dangerous causes of red-colored stools.

This post was last modified on December 2, 2024 4:43 am