Sqlite foreign key mismatch?

I've read this question and understood the referenced foreign keys to be unique, but somehow the insertion to table are still throwing foreign key mismatch errors:

CREATE TABLE medication (
med_id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, 
med_name VARCHAR (20) NOT NULL, 
dosage VARCHAR (10)
);    

CREATE TABLE disease (
dis_id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, 
disease_name VARCHAR (20) NOT NULL
);    

CREATE TABLE dis_med (
disease_id int NOT NULL, 
medication_id int NOT NULL, 
CONSTRAINT PK_dis_med PRIMARY KEY (disease_id, medication_id), 
CONSTRAINT FK_dis FOREIGN KEY (disease_id) REFERENCES disease (dis_id), 
CONSTRAINT FK_med FOREIGN KEY (medication_id) REFERENCES medication (med_id));

CREATE TABLE user_disease (
user_id REFERENCES user (user_id), 
dis_id REFERENCES disease (dis_id), 
med_id REFERENCES dis_med(medication_id),
CONSTRAINT PK_dis_user PRIMARY KEY (user_id, dis_id)
);

Through the list in the question I cited:

• the parent table (medication, disease) exists.
• the parent columns exist
• the child table references all of the primary key columns in the parent table

Update1
I was able to insert data and bypass the error by altering the user_disease table by composite foreign key. I'd appreciate it if someone can point out what's the best design here. Many thanks in advance!

CREATE TABLE user_disease (
user_id REFERENCES user (user_id), 
dis_id REFERENCES disease (dis_id), 
med_id REFERENCES dis_med(medication_id),
CONSTRAINT FK_dis_med FOREIGN KEY REFERENCES dis_med(disease_id, medication_id),
CONSTRAINT PK_dis_user PRIMARY KEY (user_id, dis_id)
);