The bleach in a laundry detergent tablet would probably cause burns to your digestive tract, which can induce painful vomiting. If the bleach is concentrated, the damage will be worse. If the inflammation of the esophagus is bad enough, it will narrow the opening, and digestion will be restricted. One study suggests that the ingestion of bleach, or other caustic materials, could cause "esophageal perforation" in the long-term.
Ingesting isn’t the only option here, by the way. You can breathe these substances into your lungs too, wherein similar irritant/corrosive effects will manifest themselves – something that can cause varying degrees of respiratory distress and damage.
One study even notes that the various other chemicals, including some detergents (like ethoxylated alcohol) and other compounds, like propylene glycol, can lead to the depression of the central nervous system. This means that you can become drowsy or, in a serious case, you can fall into a coma.
The full range of effects, and what chemicals specifically cause them, is unknown at this time – and we’ve reached out to medical professionals for comment. Nevertheless, reports on individual cases, like this one, generally come to the same conclusion: namely, there is a “potential for significant toxicity” from ingesting these tablets.
Oh, The Humanity!
As noted in a recent report by the US Centers for Disease Control and Prevention (CDC), the median age for tablet/pod-based exposure to laundry detergents was 3 years of age. The reason for this is that the pods are extremely vibrant and colorful, and toddlers wonder what would happen if such an aesthetically garish product was placed in their mouths.
As a teenager or an adult, you don’t have that excuse. Don’t do it – you’re engaging in an activity whose click-based rewards simply don’t outweigh the risks.