13 years old, often with abdominal pain sometimes accompanied by fever, what disease is this?

Patient's question:

Patient is male, 13 years old, previously often had abdominal pain, recently often accompanied by fever

Doctor's answer:

Using antispasmodic drugs (such as cimetropium bromide) can block muscarinic receptors in smooth muscle, and can also directly act on smooth muscle to relieve smooth muscle spasm. For those who do not respond, bisoprolol hydrochloride can be used. As an anticholinergic drug, it has atropine-like spasm-relieving effects and a certain central calming effect, and has a certain therapeutic effect in the treatment of intestinal spasms.