Brief Answer:
acute gastroenteritis/coilitis.You are constipated because you are eating less so most of the BRAT diet is absorbed by body to get energy.Once you would be on normal diet constipation would go away.Lastly both loose motion and constipation can be there in colon infection.

Detailed Answer:
Hello and thanks for asking query on HealthcareMagic my dear patient,
I have seen your details and appreciate your concern,
Your husband is suffering from stomach flu.
Its the inflammation of intestine(colon),This inflammation is caused by infection.Most of the time infection is viral and self limiting but sometimes overlapping bacterial and protozoal infection is also there therefore he is given antibiotics.
As intestines are inflamed cramping would be there.Some patients has loose motions while some may have constipation.
Add isabghul husk fiber 10 mg thrice daily(over the counter).Initially soak it in XXXXXXX warm water and give him.It acts as a bulk forming agent.
Secondly start a probiotic like Econorm twice daily.It would improve and rejenuvate good bacteria's in gut and would cause fast recovery.

Antibiotic should be-
Ofloxacin/Norfloxacin
Metronidazole
Dicyclomine anti spasmodic(you can confirm with your treating doctor).

To stop liquid motions give him imodium 4mg three times a day(over the counter).
With every stool give him 200ml Oral rehydration solution/Electral.
Keep him on soft diet.
Follow up after 2-3 days.
Hope i was helpful,
Follow ups are welcome,
Thank you!

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