Stroke with concurrent gastrointestinal infection: This is a likely diagnosis because the left-sided weakness could be indicative of a stroke, and the dysentery could be a separate, concurrent infection. The combination of neurological deficits and gastrointestinal symptoms can sometimes occur together, especially in the context of an infectious process that might precipitate or be a consequence of the stroke.

Neurocysticercosis with intestinal infection: Neurocysticercosis, caused by the pork tapeworm (Taenia solium), can lead to neurological symptoms including weakness, and if the patient has a concurrent intestinal infection, it could present with dysentery-like symptoms.
Spinal cord lesion with gastrointestinal infection: A spinal cord lesion, due to trauma, infection, or other causes, could result in left-sided weakness, and a separate gastrointestinal infection could cause dysentery.

Spinal epidural abscess: This is a medical emergency that can cause neurological deficits, including weakness, and might be accompanied by systemic signs of infection, including gastrointestinal symptoms. Early diagnosis and treatment are crucial to prevent permanent neurological damage.
Meningitis or encephalitis with gastrointestinal symptoms: Infections like meningitis or encephalitis can present with a wide range of symptoms, including neurological deficits and gastrointestinal symptoms. These conditions are medical emergencies requiring prompt diagnosis and treatment.

Whipple's disease: A rare, systemic bacterial infection (Tropheryma whipplei) that can affect the gastrointestinal system, causing dysentery-like symptoms, and the central nervous system, leading to various neurological symptoms, including weakness.
Neurosyphilis with gastrointestinal involvement: In late stages, syphilis can affect the central nervous system, causing a variety of neurological symptoms. While less common, it could also be associated with gastrointestinal symptoms if there is concurrent syphilitic involvement of the gut.