Musculoskeletal strain: Given the age and presentation of stinging pain in the left lower abdomen near the pelvis, a musculoskeletal strain from overuse or injury is a common and plausible explanation. This could be due to physical activity, sports, or even lifting heavy objects.

Urinary tract infection (UTI): Although less common in young males, a UTI could cause abdominal pain, especially if the infection has moved up to the kidneys (pyelonephritis).
Inguinal hernia: An inguinal hernia can cause pain in the lower abdomen that may radiate to the groin area, which could be described as near the pelvis.
Constipation or gastrointestinal issues: Constipation or other gastrointestinal issues like irritable bowel syndrome (IBS) could cause abdominal pain, although the description of "stinging" is less typical.

Testicular torsion: This is a medical emergency that requires immediate attention. Although the pain is typically acute and severe, located in the testicle, and may radiate to the abdomen, it's crucial not to miss this diagnosis due to its potential for causing infertility and requiring urgent surgical intervention.
Appendicitis: While the pain of appendicitis usually starts near the navel and then moves to the lower right abdomen, it's essential to consider this diagnosis, especially if the appendix is located in an atypical position (retrocecal), which could cause pain to be perceived in the lower left abdomen.
Ectopic pregnancy: Although extremely rare in males, if the patient has undergone gender-affirming surgery or has other specific medical conditions, ectopic pregnancy could be considered, albeit highly unlikely.

Ovarian torsion or ovarian cysts: These conditions are typically found in females but could be considered in patients with specific medical histories or conditions (e.g., ovotestes in disorders of sex development).
Diverticulitis: This condition is more common in older adults but can occur in younger individuals, especially those with a family history or specific risk factors. It causes inflammation of the diverticula in the digestive tract and can lead to severe abdominal pain, usually on the left side.
Inflammatory bowel disease (IBD): Conditions like Crohn's disease or ulcerative colitis can cause chronic abdominal pain and are typically accompanied by other symptoms such as changes in bowel habits, blood in stool, and weight loss.