Given the following pandas dataframe
Family	Scientific_name	Local_name	Diseases_treated	Part_used	Preparation	Administration
0	Anacardiaceae	Sorindeia madagascariensis DC.	Voasirindrina	Diarrhea	Leaves	Decoction	Oral
1	Anacardiaceae	Sorindeia madagascariensis DC.	Voasirindrina	Stomach-ache	Leaves	Decoction	Oral
2	Annonaceae	Annona muricata L.	Voatsokina, goronoa	Stomach-ache	Leaves	Decoction	Oral
3	Aphloiaceae	Aphloia theiformis (NAME_1) Benn.	Fandramanana	Stomach-ache	Leaves	Decoction	Oral
4	Apiaceae	Centella asiatica (L.) Urb.	Talapetraka	Stomach-ache	Leaves	Decoction	Oral
5	Apocynaceae	Catharanthus roseus (L.) G. Don	Arivotaombelona	Malaria	Leaves	Decoction	Oral
6	Apocynaceae	Petchia erythrocarpa (Vatke) Leeuwenb.	Hintona	Malaria	Leaves	Decoction	Oral
7	Apocynaceae	Petchia erythrocarpa (Vatke) Leeuwenb.	Hintona	Malaria	Bark	Infusion	Oral
8	Arecaceae	NAME_2 nucifera L.	Coco	Diarrhea	Leaves	Infusion	Oral
9	Arecaceae	NAME_2 nucifera L.	Coco	Stomach-ache	Leaves	Decoction	Oral
10	Arecaceae	Raphia farinifera (Gaertn.) Hyl.	Rafia	Diarrhea	Fruit	Decoction	Oral
11	Asteraceae	Cyanthillium cinereum (L.) H. Rob.	Ramitsiry	Stomach-ache	Whole plant	Decoction	Oral
12	Asteraceae	Elephantopus scaber L.	Angadoha	Diarrhea	Leaves	Crush and heat	Oral
13	Asteraceae	Elephantopus scaber L.	Angadoha	Stomach-ache	Leaves	Heat and press	Oral
14	Asteraceae	Emilia citrina DC.	Tsihontsihona	Malaria	Whole plant	Decoction	Oral
15	Asteraceae	Emilia citrina DC.	Tsihontsihona	Stomach-ache	Leaves	Decoction	Oral
Generate python code to answer "Give  local names of all plants that treat 'stomach-ache'?" and run it on the given dataframe and give the answer to the question
