In a case of a 9-month-old child with a palpable mass and 'jelly-like' stools, what is the most likely diagnosis?

In a 9-month-old child presenting with a palpable abdominal mass and 'jelly-like' stools, intussusception is the most likely diagnosis. Intussusception occurs when a part of the intestine telescopes into an adjacent segment, leading to obstruction. This condition is particularly common in young children and can lead to significant complications if not addressed promptly.

The 'currant jelly' stools are a characteristic symptom resulting from the mixing of blood and mucus that occurs when the blood supply to the affected segment of the intestine is compromised. The palpable mass, often described as a "sausage-shaped" mass in the abdomen, corresponds to the area where the intussuscepted bowel is located.

The other conditions listed do not typically present with these specific symptoms. Pyloric stenosis primarily causes projectile vomiting and does not typically result in a palpable mass in the abdomen or 'jelly-like' stools. Appendicitis, while it can occur in young children, usually presents with right lower quadrant pain and often leads to fever, nausea, and vomiting, rather than the described bowel changes. Malabsorption can lead to various gastrointestinal symptoms, but it would not present with a palpable mass or jelly-like stools in this specific manner. Thus, the