Praise be to Allah.

Firstly:

The humanity of the Prophets, and their vulnerability to sickness, hunger and passing wind and the like, is a matter on which there is consensus among the Muslims, and it is also stated in the Qur’anic text. Allah, may He be exalted, says (interpretation of the meaning):

“The Messiah, son of Mary, was not but a messenger; [other] messengers have passed on before him. And his mother was a supporter of truth. They both used to eat food. Look how We make clear to them the signs; then look how they are deluded”

[al-Maa’idah 5:75]

“Their messengers said to them, We are only men like you, but Allah confers favor upon whom He wills of His servants. It has never been for us to bring you evidence except by permission of Allah. And upon Allah let the believers rely”

[Ibraaheem 14:11]

“Say, O [Muhammad], "I am only a man like you to whom it has been revealed that your god is but one God; so take a straight course to Him and seek His forgiveness." And woe to those who associate others with Allah”

[Fussilat 41:6].

Ibn Taymiyah said: The Prophets were vulnerable to sickness, hunger, forgetfulness and the like, according to scholarly consensus.

End quote from ar-Radd ‘ala al-Bakri (1/306).

The Prophets were only human, like any other humans, and there happened to them what happens to all humans. So they fell sick, they experienced hunger, they sometimes forgot things, and so on. Allah, may He be exalted, says (interpretation of the meaning):

“Their messengers said to them, We are only men like you, but Allah confers favor upon whom He wills of His servants”

[Ibraaheem 14:11].

Allah, may He be exalted, said concerning Ayyoob (peace be upon him):

“And remember Our servant Job, when he called to his Lord, ‘Indeed, Satan has touched me with hardship and torment’”

[Saad 38:41]

“And [mention] Job, when he called to his Lord, ‘Indeed, adversity has touched me, and you are the Most Merciful of the merciful’”

[al-Anbiya’ 21:83].

And Allah, may He be glorified and exalted, tells us that the Prophets had wives and children, as He says (interpretation of the meaning):

“And We have already sent messengers before you and assigned to them wives and descendants”

[ar-Ra‘d 13:38].

Indeed, they used to eat food and walk in the markets, as Allah, may He be exalted, says (interpretation of the meaning):

“And We did not send before you, [O Muhammad], any of the messengers except that they ate food and walked in the markets”

[al-Furqaan 25:20].

Allah, may He be glorified and exalted, tells us that Adam (peace be upon him) forgot, as He says (interpretation of the meaning):

“And We had already taken a promise from Adam before, but he forgot; and We found not in him determination”

[Ta-Ha 20:115].

And He, may He be exalted, tells us of Moosa (peace be upon him) and his servant:

“But when they reached the junction between them, they forgot their fish”

[al-Kahf 18:61].

All these attributes highlight the humanity of the Prophets, and indicate that they were vulnerable to the same things as all other humans, except that they received revelation, as Allah, may He be exalted, instructed His Prophet to tell us:

“Say, ‘I am only a man like you, to whom has been revealed that your god is one God’”

[al-Kahf 18:110].

The Prophet (blessings and peace of Allah be upon him) said: “I am human like you. I remember as you remember and I forget as you forget.” Narrated by Muslim (572).

End quote from al-Mawsoo‘ah al-‘Aqdiyyah (4/39).

Secondly:

Undoubtedly the fact that the Messengers were human implies by necessity that they had the characteristics that no human can be without, which means that they ate, drank, slept, got married, and had children; they needed what all humans need of food, drink, and the excretion of waste, as happens to all humans, because that is the inevitable outcome of eating and drinking.

“And We sent not before you, [O Muhammad], except men to whom We revealed [the message], so ask the people of the message if you do not know.

And We did not make the prophets forms not eating food, nor were they immortal [on earth]”

[al-Anbiyaa’ 21:7-8].

By the same token, they were born as humans are born; they had fathers and mothers, paternal uncles and paternal aunts, maternal uncles and maternal aunts; they got married and had children:

“And We have already sent messengers before you and assigned to them wives and descendants”

[ar-Ra‘d 13:38].

One of the implications of that is that they needed to expel waste matter, namely urine, faeces and the like.

That is mentioned in the hadiths that speaks of purification and minor impurity; these matters are so well-known that there is no need to mention them here.

One example is the report narrated by Muslim in his Saheeh (271) from Anas ibn Maalik, who said: The Messenger of Allah (blessings and peace of Allah be upon him) would go to a secluded place to relieve himself, and a young boy like myself and I would bring a vessel of water, and he would clean himself with the water.

In Saheeh al-Bukhaari (156) it is narrated from ‘Abdullah ibn Mas‘ood (may Allah be pleased with him) that the Prophet (blessings and peace of Allah be upon him) would go to a secluded place to relieve himself and instruct me to bring him three pebbles. I found two pebbles, and I looked for a third but could not find one, so I picked up a piece of dung and brought it to him. He took the two pebbles and threw away the dung.

And Allah knows best.